OpenVZ Virtuozzo Containers Wiki - User contributions [en]

Testimonials

2010-01-22T14:23:02Z

Mperkel: /* OpenVZ keeps my spam filtering business running */ new section

'''Following are some comments we've received from OpenVZ users.'''

----

I'm curious. For the past few months, people@openvz.org have discovered
(and fixed) an ongoing stream of obscure but serious and quite
long-standing bugs.

How are you discovering these bugs?

''Andrew Morton, [http://openvz.org/pipermail/devel/2007-July/006281.html Devel mainling list]''

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OpenVZ, which also is vying for inclusion in the mainstream Linux kernel, would complement Xen well and has impressed me in the initial testing I've conducted.

''Jason Brooks, Senior Analyst, Ziff Davis. [http://www.eweek.com/c/a/Linux-and-Open-Source/Red-Hat-Isnt-Exhibiting-XenOphobia/ eweek.com]''

----

I just wanted to congratulate you and the rest of the OpenVZ team for your
excellent, excellent work. We are now have an OpenVZ subject in our 120
hours Total Linux course here at the Bluepoint Foundation, and our
students really appreciate the work you've done. I'm learning a lot from
lurking in the devel list too. Thanks again and keep 'em coming! :D

''Engels Antonio, [http://bluepoint.com.ph/ Bluepoint Foundation]''

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I would say, OpenVZ is '''United States of Linux''' because i can run all my lovely different type of GNU/Linux distributions(States) on '''one single machine''' with '''one kernel''' model. As stable as guaranteed for production server and handy for software development (well no more dual, tri, quad boot partition). After all, it is just a good quality software piece for Linux User. Again, welcome to '''United States of Linux''' world!!

''Victor, System Admin, [http://www.kholix.com kholix.com]''

----

Thanks for producing OpenVZ, we use it ourselves at PlanetMirror and
find that it's fantastic.

''Robert McLeay, PlanetMirror.com stuff''

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OpenVZ is about the greatest thing we've ever found, and we're SO glad for it.

''Gregor Mosheh, HostGIS'' [https://openvz.org/pipermail/users/2007-August/001104.html]

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OpenVZ has me seriously impressed, I was looking to try virtualisation technology and got OpenVZ up and running in only 3 trips to the coffee machine! ''-barf''

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We've been running OpenVZ in a production environment for a few years for a multitude of tasks. It's been nothing short of amazing, stable, and resource friendly! Thanks to all those who have contributed to make OpenVZ even better over the years!

''Eric Thern, Technical Director, [http://www.zoidial.com Zoidial Hosting and VPS]''

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Hello all, just downloaded and installed OpenVZ, and i must say its a big improvement over other container systems that i have tested IMHO.
[http://forum.openvz.org/index.php?t=tree&goto=646&#msg_646]

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Virtuozzo and openvz are wonderful - I don't know why more people aren't
using them. I hear a lot of hype for xen and usermode but
virtuozzo/openvz is so great for many common needs.
[http://forum.openvz.org/index.php?t=rview&goto=650#msg_650]

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For my needs, OpenVZ is better than Xen. The one-kernel approach conserves memory, leaving more for applications. And having all container in one disk partition saves disk space. A surprise bonus was the template cache management with yum. The ease of keeping templates updated and quickly installing new operating environments is yummy!
[http://forum.openvz.org/index.php?t=rview&goto=3119#msg_3119]

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I agree with you very much. I would say for enterprise use where cost/efficiency is not a factor, Xen has an edge over VZ. However for a service provider or other situation where CPU/RAM/DISK resources are shared among environments to ensure profitability/efficiency, openvz is far superior. Also, VZ is much simpler to use, and all of the command line utilities are well documented.
[http://forum.openvz.org/index.php?t=tree&th=572&mid=3122]

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Last week when we were in limbo about what to do, it was decided to try out XEN Virtualization. From what is written in the press the Xen system has alot of promise, Features such as opensource with live migration and backups sounds great; but was far too complicated to get working in our configuration. OpenVZ was the only virtual server system that was simple to install and get working.
[http://forum.openvz.org/index.php?t=msg&goto=568#msg_568]

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It still amazes me how well OpenVZ works.
[http://forum.openvz.org/index.php?t=msg&th=368&#msg_2086]

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[03:30:15] <pookey> well, I've been using openvz for all of about an hour, and I'm pretty impressed so far :)<br/>
''from #openvz IRC channel''

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I am playing around for years with all major virtualization environments like all VMware products, Microsoft and several xen based solutions. But OpenVZ is the overall winner. [http://blog.openvz.org/14313.html]

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I messed around with VMWare and Xen. I found VMWare to be somewhat over kill and Xen was damned hard to get working. The user community on the Xen mailing list is rather hostile. It looked like A number of people hang out there for the sole purpose of flaming the clueless.

I've found the OpenVZ folks to be very helpful and knowledgeable. OpenVZ is simple to install and get running. It pretty much satisfies my needs. [http://blog.openvz.org/14313.html?thread=17897#t17897]

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I'm a sysadm and have always used xen/qemu/virtualbox/vmware server for my VMs and my customer's ones. Yesterday I decided to give OpenVZ a try and... I'm amazed. It's fast, easy and reliable.Live migration works like a charm and the use of rsync assures low data transfers. Great. [http://forum.openvz.org/index.php?t=tree&goto=14724&#msg_14724] ''Stefano Marinelli, http://www.dragas.net''

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OpenVZ is one of the few pieces of software that I truly love. It works wonderfully. It should become part of the mainline kernel. ''Nick Andrew, http://www.nick-andrew.net''

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And thanks again for OpenVZ. Our business couldn't do what we do, as well as we do, with VMWare or Xen. ''Gregor Mosheh'', System Administrator, HostGIS cartographic development & hosting services.

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Thank you for OpenVZ by the way... it is awesome. It saves me hours of work every day. ''Eric Gearhart, http://nixwizard.net''

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For us at [http://www.signet.nl Signet], OpenVZ is ideal as a virtualization platform as it's open-source, no vendor lock-in's and great performance. It perfectly integrates into our high-availability SAN and server setup so it's great. ''Remco Bressers, http://www.signet.nl''

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Indira Gandhi National Open University, India (IGNOU) is the world's largest open university in terms of student enrolments (2.5 + million approx.) for different programmes. Catering web based services to such large student fraternity is indeed a hard task. The systems and services were heavily biased towards proprietary corporations products, thereby, aggravating the quality of service to its intended audience. Moreover, virtualization was a blackbox to the IT department of IGNOU, until May 2009. Thereafter the entire networks and systems were stunned to see at least 4 Mediawiki sites , 1 tomcat based Java application, 2 Subversion server for in-house development & networking team, 1 egroupware server on a single SUN Fire X 4140 powered by Debian & OpenVZ.
All the services are live with downtime of 5 hours(due to electrical outage, ISP downtime) since May 2009 till date. That makes 99.91 % uptime.
Kudos to OpenVZ team for making this possible.
--[[User:Sukant.kole|Sukant Kole]], [http://aciil.ignou.ac.in ACIIL]23:37, 13 January 2010 (UTC)

== OpenVZ keeps my spam filtering business running ==

I'm in the spam filtering business, [http://www.junkemailfilter.com Junk Email Filter] and I'm running OpenVZ on everything. I love the virtualization for several reasons. In spam filtering there is a lot of redundancy and duplication across machines. I have a network of front end Exim servers as a front end MTA. I also have Spam Assassin virtual servers, regular name servers, caching name servers, RBL servers, post processing spam servers, and servers gathering statistics and building white and black lists.

By modularizing the functions and creating multiple OpenVZ servers I can move virtual machines from computer to computer to balance loads across several physical servers. I can create servers with different permissions so that many of these servers are more secure in that they only have root as the only real login user. If I need to expand I just buy more computers and populate them with the right combination of virtual servers.

I chose OpenVZ over other virtualizations because OpenVZ is fast and efficient. It is in fact the most fast an efficient because it sacrifices some of the features of true virtualization. It's Linux only and has a single kernel. But my needs are Linux only and OpenVZ has almost no overhead at all. It doesn't leave memory fragmented into virtual machines that never use all their ram. Instead the memory limits are just caps and memory usage depends on what you run.It's fast, it's simple, and it just works.

Oracle 10g VE

2008-08-29T18:05:43Z

Mperkel: /* Reset resource limits */

This is just a listing of steps taken to create a fully functional
Oracle container.

== Create the container on the [[host system]] ==

vzctl create 1001 --ostemplate centos-4-i386-default
vzctl set 1001 --userpasswd root:password --save
vzctl set 1001 --hostname ve-oracle.example.com --save
vzctl set 1001 --ipadd 192.168.0.62 --save

== Reset resource limits ==

I decided to have max limits to avoid problems during installation.
Once the installation is
done and the system left running for some time, these limits can be
adjusted.

{{Note|setting the UBC limits to "unlimited" value like below can only be done
on a trusted single-container machine, and can create problems. For more info
about UBC, see [[Resource shortage]] and [[UBC]].}}

vzctl set 1001 --kmemsize 2147483647:2147483647 --save
vzctl set 1001 --lockedpages 2147483647:2147483647 --save
vzctl set 1001 --privvmpages 2147483647:2147483647 --save
vzctl set 1001 --shmpages 2147483647:2147483647 --save
vzctl set 1001 --numproc 2147483647:2147483647 --save
vzctl set 1001 --numtcpsock 2147483647:2147483647 --save
vzctl set 1001 --numflock 2147483647:2147483647 --save
vzctl set 1001 --numpty 2147483647:2147483647 --save
vzctl set 1001 --numsiginfo 2147483647:2147483647 --save
vzctl set 1001 --tcpsndbuf 2147483647:2147483647 --save
vzctl set 1001 --tcprcvbuf 2147483647:2147483647 --save
vzctl set 1001 --othersockbuf 2147483647:2147483647 --save
vzctl set 1001 --dgramrcvbuf 2147483647:2147483647 --save
vzctl set 1001 --numothersock 2147483647:2147483647 --save
vzctl set 1001 --dcachesize 2147483647:2147483647 --save
vzctl set 1001 --numfile 2147483647:2147483647 --save
vzctl set 1001 --numiptent 2147483647:2147483647 --save

Or you can set these limits in your vz.conf file:

# Primary parameters
AVNUMPROC="unlimited:unlimited"
NUMPROC="unlimited:unlimited"
NUMTCPSOCK="unlimited:unlimited"
NUMOTHERSOCK="unlimited:unlimited"
VMGUARPAGES="unlimited:unlimited"

# Secondary parameters
KMEMSIZE="unlimited:unlimited"
TCPSNDBUF="unlimited:unlimited"
TCPRCVBUF="unlimited:unlimited"
OTHERSOCKBUF="unlimited:unlimited"
DGRAMRCVBUF="unlimited:unlimited"
OOMGUARPAGES="unlimited:unlimited"

# Auxiliary parameters
LOCKEDPAGES="unlimited:unlimited"
SHMPAGES="unlimited:unlimited"
PRIVVMPAGES="unlimited:unlimited"
NUMFILE="unlimited:unlimited"
NUMFLOCK="unlimited:unlimited"
NUMPTY="unlimited:unlimited"
NUMSIGINFO="unlimited:unlimited"
DCACHESIZE="unlimited:unlimited"

PHYSPAGES="unlimited:unlimited"
NUMIPTENT="unlimited:unlimited"

{{Inconsistent UBC warning}}

== Start the container ==
vzctl start 1001

== Update <code>/etc/resolv.conf</code> on the container

Put the following into your container's /etc/resolv.conf:

search example.com
nameserver <ip address of your name server>

== Install Required Packages ==

vzyum 1001 install binutils compat-db gcc gcc-c++ glibc \
glibc-common libstdc++ libstdc++-devel gnome-libs make \
pdksh sysstat libaio xscreensaver openmotif21 xorg-x11-xfs \
usbutils urw-fonts shared-mime-info perl-libwww-perl \
perl-XML-Parser perl-URI perl-HTML-Tagset perl-HTML-Parser \
patch lvm2 intltool libIDL libart_lgpl libbonobo xterm \
libcap libcroco libgnomecanvas libexif libgnomecups \
libgnomeprint22 libsoup libwnck libxklavier

== Check the following rpms are installed on the container ==

vzctl exec 1001 rpm -q binutils gcc gcc-c++ glibc gnome-libs \
libstdc++ libstdc++-devel make pdksh sysstat xscreensaver libaio

== Add Oracle User/Group ==

vzctl exec 1001 /usr/sbin/groupadd oinstall
vzctl exec 1001 /usr/sbin/groupadd dba
vzctl exec 1001 /usr/sbin/useradd -m -g oinstall -G dba oracle
vzctl exec 1001 id oracle

== Set Password for the Oracle user ==

vzctl exec 1001 passwd oracle

== Create Directories for Oracle Home/Data and the download directory ==

vzctl exec 1001 mkdir /home/oracle/10gR2_db
vzctl exec 1001 mkdir -p /u01/app/oracle/product/10.2.0/db_1
vzctl exec 1001 mkdir /u01/app/oracle/oradata
vzctl exec 1001 chown -R oracle:oinstall /u01/app/oracle /home/oracle/10gR2_db
vzctl exec 1001 chmod -R 775 /u01/app/oracle /home/oracle/10gR2_db
vzctl exec 1001 ln -s /usr/lib/libstdc++.so.6.0.3 /usr/lib/libstdc++.so.5

== Put these values in /etc/sysctl.conf on the HN ==

Put these values in /etc/sysctl.conf on the HN:

kernel.shmall = 2097152
kernel.shmmax = 536870912
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 65536
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default=262144
net.core.wmem_default=262144
net.core.rmem_max=262144
net.core.wmem_max=262144

Then execute on the HN the following command:

/sbin/sysctl -p

At this point the container is ready for Oracle installation.
We take a backup of the container at this point in case we need to rebuild the
system or do a clean Oracle install.

== Shutdown the container and take a backup ==

vzctl stop 1001
cd /u01/backups
tar czpvf ve-1001-preOracle.tar.gz /vz/private/1001/ /etc/vz/conf/1001.conf

== Start the container again ==

vzctl start 1001

== Put oracle distro into the container ==

Copy the downloaded Oracle zip file to the container and change its
ownership to "oracle" on the container.

cp /u01/software/10201_database_linux32.zip /vz/private/1001/home/oracle/10gR2_db/
vzctl exec 1001 chown oracle:oinstall /home/oracle/10gR2_db/10201_database_linux32.zip

== Start installation ==

Now login as oracle on the ve-1001, and run the following commands:

cd /home/oracle/10gR2_db
unzip 10201_database_linux32.zip
cd database/
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
export DISPLAY=192.168.0.149:0

Make sure you can run xterm, then:

./runInstaller

'''When prompted to run scripts as root. Login as root and execute'''

export DISPLAY=192.168.0.149:0
/u01/app/oracle/oraInventory/orainstRoot.sh
/u01/app/oracle/product/10.2.0/db_1/root.sh

'''Update oracle's profile with the following'''

cd
vi /home/oracle/.bashrc
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH
export PATH=$ORACLE_HOME/bin:$PATH
export ORACLE_SID=orcl

'''Delete installation files (optional)'''

cd /home/oracle/10gR2_db
rm -rf database

'''Time to take another backup of the container on the [[hardware node]].'''

This backup will allow you to restore the container to the point where no
database has yet been created.

vzctl stop 1001
cd /u01/backups
tar czpvf ve-1001-postOracleSoftware.tar.gz \
/vz/private/1001/ /etc/vz/conf/1001.conf

Start the container

vzctl start 1001

'''Login as oracle and create the database'''

export DISPLAY=192.168.0.149:0
dbca

'''Create listener'''

netca

'''Now take another backup on the HN node'''

vzctl stop 1001
cd /u01/backups
tar czpvf ve-1001-postOracleDatabase.tar.gz \
/vz/private/1001/ /etc/vz/conf/1001.conf

== Oracle Help ==

* [http://www.orafaq.com/forum Ask questions on the Oracle Forum]
* [http://www.orawiki.com/ Oracle Wiki]

[[Category:HOWTO]]

Oracle 10g VE

2008-08-29T18:05:06Z

Mperkel: /* Reset resource limits */

This is just a listing of steps taken to create a fully functional
Oracle container.

== Create the container on the [[host system]] ==

vzctl create 1001 --ostemplate centos-4-i386-default
vzctl set 1001 --userpasswd root:password --save
vzctl set 1001 --hostname ve-oracle.example.com --save
vzctl set 1001 --ipadd 192.168.0.62 --save

== Reset resource limits ==

I decided to have max limits to avoid problems during installation.
Once the installation is
done and the system left running for some time, these limits can be
adjusted.

{{Note|setting the UBC limits to "unlimited" value like below can only be done
on a trusted single-container machine, and can create problems. For more info
about UBC, see [[Resource shortage]] and [[UBC]].}}

vzctl set 1001 --kmemsize 2147483647:2147483647 --save
vzctl set 1001 --lockedpages 2147483647:2147483647 --save
vzctl set 1001 --privvmpages 2147483647:2147483647 --save
vzctl set 1001 --shmpages 2147483647:2147483647 --save
vzctl set 1001 --numproc 2147483647:2147483647 --save
vzctl set 1001 --numtcpsock 2147483647:2147483647 --save
vzctl set 1001 --numflock 2147483647:2147483647 --save
vzctl set 1001 --numpty 2147483647:2147483647 --save
vzctl set 1001 --numsiginfo 2147483647:2147483647 --save
vzctl set 1001 --tcpsndbuf 2147483647:2147483647 --save
vzctl set 1001 --tcprcvbuf 2147483647:2147483647 --save
vzctl set 1001 --othersockbuf 2147483647:2147483647 --save
vzctl set 1001 --dgramrcvbuf 2147483647:2147483647 --save
vzctl set 1001 --numothersock 2147483647:2147483647 --save
vzctl set 1001 --dcachesize 2147483647:2147483647 --save
vzctl set 1001 --numfile 2147483647:2147483647 --save
vzctl set 1001 --numiptent 2147483647:2147483647 --save

Or you can set these limits in your vz.conf file:

# Primary parameters
AVNUMPROC="unlimited:unlimited"
NUMPROC="unlimited:unlimited"
NUMTCPSOCK="unlimited:unlimited"
NUMOTHERSOCK="unlimited:unlimited"
VMGUARPAGES="unlimited:unlimited"

# Secondary parameters
KMEMSIZE="2G:2G"
TCPSNDBUF="unlimited:unlimited"
TCPRCVBUF="unlimited:unlimited"
OTHERSOCKBUF="unlimited:unlimited"
DGRAMRCVBUF="unlimited:unlimited"
OOMGUARPAGES="unlimited:unlimited"

# Auxiliary parameters
LOCKEDPAGES="unlimited:unlimited"
SHMPAGES="unlimited:unlimited"
PRIVVMPAGES="unlimited:unlimited"
NUMFILE="unlimited:unlimited"
NUMFLOCK="unlimited:unlimited"
NUMPTY="unlimited:unlimited"
NUMSIGINFO="unlimited:unlimited"
DCACHESIZE="unlimited:unlimited"

PHYSPAGES="unlimited:unlimited"
NUMIPTENT="unlimited:unlimited"

{{Inconsistent UBC warning}}

== Start the container ==
vzctl start 1001

== Update <code>/etc/resolv.conf</code> on the container

Put the following into your container's /etc/resolv.conf:

search example.com
nameserver <ip address of your name server>

== Install Required Packages ==

vzyum 1001 install binutils compat-db gcc gcc-c++ glibc \
glibc-common libstdc++ libstdc++-devel gnome-libs make \
pdksh sysstat libaio xscreensaver openmotif21 xorg-x11-xfs \
usbutils urw-fonts shared-mime-info perl-libwww-perl \
perl-XML-Parser perl-URI perl-HTML-Tagset perl-HTML-Parser \
patch lvm2 intltool libIDL libart_lgpl libbonobo xterm \
libcap libcroco libgnomecanvas libexif libgnomecups \
libgnomeprint22 libsoup libwnck libxklavier

== Check the following rpms are installed on the container ==

vzctl exec 1001 rpm -q binutils gcc gcc-c++ glibc gnome-libs \
libstdc++ libstdc++-devel make pdksh sysstat xscreensaver libaio

== Add Oracle User/Group ==

vzctl exec 1001 /usr/sbin/groupadd oinstall
vzctl exec 1001 /usr/sbin/groupadd dba
vzctl exec 1001 /usr/sbin/useradd -m -g oinstall -G dba oracle
vzctl exec 1001 id oracle

== Set Password for the Oracle user ==

vzctl exec 1001 passwd oracle

== Create Directories for Oracle Home/Data and the download directory ==

vzctl exec 1001 mkdir /home/oracle/10gR2_db
vzctl exec 1001 mkdir -p /u01/app/oracle/product/10.2.0/db_1
vzctl exec 1001 mkdir /u01/app/oracle/oradata
vzctl exec 1001 chown -R oracle:oinstall /u01/app/oracle /home/oracle/10gR2_db
vzctl exec 1001 chmod -R 775 /u01/app/oracle /home/oracle/10gR2_db
vzctl exec 1001 ln -s /usr/lib/libstdc++.so.6.0.3 /usr/lib/libstdc++.so.5

== Put these values in /etc/sysctl.conf on the HN ==

Put these values in /etc/sysctl.conf on the HN:

kernel.shmall = 2097152
kernel.shmmax = 536870912
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 65536
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default=262144
net.core.wmem_default=262144
net.core.rmem_max=262144
net.core.wmem_max=262144

Then execute on the HN the following command:

/sbin/sysctl -p

At this point the container is ready for Oracle installation.
We take a backup of the container at this point in case we need to rebuild the
system or do a clean Oracle install.

== Shutdown the container and take a backup ==

vzctl stop 1001
cd /u01/backups
tar czpvf ve-1001-preOracle.tar.gz /vz/private/1001/ /etc/vz/conf/1001.conf

== Start the container again ==

vzctl start 1001

== Put oracle distro into the container ==

Copy the downloaded Oracle zip file to the container and change its
ownership to "oracle" on the container.

cp /u01/software/10201_database_linux32.zip /vz/private/1001/home/oracle/10gR2_db/
vzctl exec 1001 chown oracle:oinstall /home/oracle/10gR2_db/10201_database_linux32.zip

== Start installation ==

Now login as oracle on the ve-1001, and run the following commands:

cd /home/oracle/10gR2_db
unzip 10201_database_linux32.zip
cd database/
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
export DISPLAY=192.168.0.149:0

Make sure you can run xterm, then:

./runInstaller

'''When prompted to run scripts as root. Login as root and execute'''

export DISPLAY=192.168.0.149:0
/u01/app/oracle/oraInventory/orainstRoot.sh
/u01/app/oracle/product/10.2.0/db_1/root.sh

'''Update oracle's profile with the following'''

cd
vi /home/oracle/.bashrc
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH
export PATH=$ORACLE_HOME/bin:$PATH
export ORACLE_SID=orcl

'''Delete installation files (optional)'''

cd /home/oracle/10gR2_db
rm -rf database

'''Time to take another backup of the container on the [[hardware node]].'''

This backup will allow you to restore the container to the point where no
database has yet been created.

vzctl stop 1001
cd /u01/backups
tar czpvf ve-1001-postOracleSoftware.tar.gz \
/vz/private/1001/ /etc/vz/conf/1001.conf

Start the container

vzctl start 1001

'''Login as oracle and create the database'''

export DISPLAY=192.168.0.149:0
dbca

'''Create listener'''

netca

'''Now take another backup on the HN node'''

vzctl stop 1001
cd /u01/backups
tar czpvf ve-1001-postOracleDatabase.tar.gz \
/vz/private/1001/ /etc/vz/conf/1001.conf

== Oracle Help ==

* [http://www.orafaq.com/forum Ask questions on the Oracle Forum]
* [http://www.orawiki.com/ Oracle Wiki]

[[Category:HOWTO]]

VPN via the TUN/TAP device

2008-03-12T18:19:31Z

Mperkel: /* Granting container an access to TUN/TAP */

This article describes how to use VPN via the TUN/TAP device inside a [[container]].

== Kernel TUN/TAP support ==
OpenVZ supports VPN inside a container via kernel TUN/TAP module and device.
To allow container #101 to use the TUN/TAP device the following should be done:

Make sure the '''tun''' module has been already loaded on the [[hardware node]]:
<pre>
# lsmod | grep tun
</pre>

If it is not there, use the following command to load '''tun''' module:
<pre>
# modprobe tun
</pre>

You can also add it into /etc/modules.conf to make sure it will be loaded on every reboot automatically.

== Granting container an access to TUN/TAP ==
Allow your container to use the tun/tap device:

vzctl set 101 --devices c:10:200:rw --save
vzctl set 101 --capability net_admin:on --save

And create the character device file inside the container:

vzctl exec 101 mkdir -p /dev/net
vzctl exec 101 mknod /dev/net/tun c 10 200
vzctl exec 101 chmod 600 /dev/net/tun

== Configuring VPN inside container ==
After the configuration steps above are done it is possible to use VPN software working with TUN/TAP inside
container just like on a usual standalone linux box.

The following software can be used for VPN with TUN/TAP:
* Virtual TUNnel (http://vtun.sourceforge.net)
* OpenVPN (http://openvpn.sourceforge.net)

== External links ==
* [http://vtun.sourceforge.net Virtual TUNnel]
* [http://openvpn.sourceforge.net OpenVPN]

[[Category: HOWTO]]
[[Category: Networking]]

VPN via the TUN/TAP device

2008-03-12T18:17:25Z

Mperkel: /* Granting container an access to TUN/TAP */

This article describes how to use VPN via the TUN/TAP device inside a [[container]].

== Kernel TUN/TAP support ==
OpenVZ supports VPN inside a container via kernel TUN/TAP module and device.
To allow container #101 to use the TUN/TAP device the following should be done:

Make sure the '''tun''' module has been already loaded on the [[hardware node]]:
<pre>
# lsmod | grep tun
</pre>

If it is not there, use the following command to load '''tun''' module:
<pre>
# modprobe tun
</pre>

You can also add it into /etc/modules.conf to make sure it will be loaded on every reboot automatically.

== Granting container an access to TUN/TAP ==
Allow your container to use the tun/tap device:

vzctl set 101 --devices c:10:200:rw --save
vzctl set 101 --capability net_admin:on --save

And create the character device file inside the container:
<pre>
# vzctl exec 101 mkdir -p /dev/net
# vzctl exec 101 mknod /dev/net/tun c 10 200
# vzctl exec 101 chmod 600 /dev/net/tun
</pre>

== Configuring VPN inside container ==
After the configuration steps above are done it is possible to use VPN software working with TUN/TAP inside
container just like on a usual standalone linux box.

The following software can be used for VPN with TUN/TAP:
* Virtual TUNnel (http://vtun.sourceforge.net)
* OpenVPN (http://openvpn.sourceforge.net)

== External links ==
* [http://vtun.sourceforge.net Virtual TUNnel]
* [http://openvpn.sourceforge.net OpenVPN]

[[Category: HOWTO]]
[[Category: Networking]]

Asterisk G729

2008-03-12T17:59:00Z

Mperkel: /* Installing the Asterisk/Digium g729 codec license */

=Installing the Asterisk/Digium g729 codec license=

The open source phone software Asterisk has a unique problem when you are trying to set it up inside a VE. If you buy licenses for the G729 codec from [http://www.digium.com Digium] and run the registration program it will fail. That's because the registration process requires that it has access to the MAC address on eth0 in order to work. But there is a way around it. You can make the eth0 device appear within the VE as follows:

vzctl set $VEID --netif_add eth0 --save

This command build a line in your conf file that looks like this:

NETIF="ifname=eth0,mac=XX:XX:XX:XX:XX:XX,host_ifname=veth101.0,host_mac=YY:YY:YY:YY:YY:YY"

Initially the values of eth0 (XX) match the hardware card and the values of veth101.0 (YY) is random. The important point is that the XX values is the MAC number that Digium will see when you register your codecs. And this has the advantage of being portable from machine to machine.

You can check your virtual device from within the VE as follows:

ifconfig -a

eth0 Link encap:Ethernet HWaddr FF:12:34:56:78:90
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

When you see the eth0 device in your VE and are happy with the MAC number then you can go ahead and register your codecs and it will actually work.

[[Category: HOWTO]]

Asterisk G729

2008-03-12T17:55:35Z

Mperkel:

=Installing the Asterisk/Digium g729 codec license=

The open source phone software Asterisk has a unique problem when you are trying to set it up instide a VE. If you buy licenses for the G729 codec and run the registration program it will fail. That's because the registration process requires that it has access to the MAC address on eth0 in order to work. But there is a way around it. You can make the eth0 device appear within the VE as follows:

vzctl set $VEID --netif_add eth0 --save

This command build a line in your conf file that looks like this:

NETIF="ifname=eth0,mac=XX:XX:XX:XX:XX:XX,host_ifname=veth101.0,host_mac=YY:YY:YY:YY:YY:YY"

Initially the values of eth0 (XX) match the hardware card and the values of veth101.0 (YY) is random. The important point is that the XX values is the MAC number that Digium will see when you register your codecs. And this has the advantage of being portable from machine to machine.

You can check your virtual device from within the VE as follows:

ifconfig -a

eth0 Link encap:Ethernet HWaddr FF:12:34:56:78:90
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

When you see the eth0 device in your VE and are happy with the MAC number then you can go ahead and register your codecs and it will actually work.

[[Category: HOWTO]]

Asterisk G729

2008-03-12T17:51:03Z

Mperkel:

The open source phone software Asterisk has a unique problem when you are trying to set it up instide a VE. If you buy licenses for the G729 codec and run the registration program it will fail. That's because the registration process requires that it has access to the MAC address on eth0 in order to work. But there is a way around it. You can make eth0 appear in the VE as follows:

vzctl set $VEID --netif_add eth0 --save

This command build a line in your conf file that looks like this:

NETIF="ifname=eth0,mac=XX:XX:XX:XX:XX:XX,host_ifname=veth101.0,host_mac=YY:YY:YY:YY:YY:YY"

Initially the values of eth0 (XX) match the hardware card and the values of veth101.0 (YY) is random. The important point is that the XX values is the MAC number that Digium will see when you register your codecs. And this has the advantage of being portable from machine to machine.

You can check your virtual device as follows:

ifconfig -a

When you see the eth0 device in your VE and are happy with the MAC number then you can go ahead and register your codecs and it will actually work.

[[Category: HOWTO]]

Asterisk G729

2008-03-12T17:43:59Z

Mperkel: New page: The open source phone software Asterisk has a unique problem when you are trying to set it up instide a VE. If you buy licenses for the G729 codec and run the registration program it will ...

VPS vs Dedicated

2007-02-03T22:41:28Z

Mperkel:

Although I am somewhat of a new user to the VPS world I thought I'd write a short article giving an overview of why use VPS instead of dedicated servers for those of you who are involved in the hosting business or people thinking about leasing a VPS server. Here I will address misconceptions I had about VPS and talk about how my perspective on VPS is changing.

Who am I? This article originally written by [http://www.perkel.com Marc Perkel] - a new VPS user - expressing my overview of OpenVZ from my perspective as a new user talking to other new users about my experience in learning this new environment. I am not an OpenVZ expert and I want to write this while I'm still new to OpenVZ so I can express my view from a new user's perspective. If you are just reading about VPS for the first time I am not that far ahead of you. This article is an attempt by me to give back a little to those who created this free software and give you new people anoverview of the big picture as I learn this myself.

= Why use Virtual Private Servers instead of Dedicated Servers =

Like many of you when I first heard of the idea of VPS I pictured it is some small lame server that is sold to 12 year olds trying to start hosting companies on the cheap. It had never quite caught my attention until I decided I needed a remote name server and all I needed was enough of a server to run bind, but didn't want to by a dedicated box just to do that. So I got a VPS based on Virtuozzo for $80/year and it worked great.

In the process however I started understanding the VPS concept and it became apparent that this is more that just a tool to create little servers. The way I see it VPS can replace dedicated servers in many situations in a data center and do a better job than dedicated. You can actually give the customer more horsepower and better hosting than selling them a small dedicated box. (Of course big customers will still need their own server.)

I don't own a data center business myself but I have a friend who does and I colo several servers there. He has several racks of some old Celeron boxes with 512 mgs of ram and one or two 80 gig drives depending of if the customer has any concept of backups, which most of them don't. I'm looking at the racks of Celerons and P4s thinking that each rack could be consolidated into a single modern server and that the customers would actually have a better server than the one they are on now. And the cost saving is tremendous.

= Advantages of VPS =

Most small dedicated servers are a waste of resources. People buy bigger servers than they need and the excess capacity is wasted. These servers take both space an power which is expensive in a data center and you have hardware costs assiciated with each server that you have to recoup. People often don't do any backups so after several years the hard drive fails and they lose everything. And it's your fault for not backing them up in the first place.

Imagine a rack of 16 Celeron boxes with 80 gig drives being replaced by a Dual Core Athlox X2 with 8 gigs of ram and 4 500gb SATA 2 drives running in a raid 10 configuration. (Writing this in Feb of 2007 for future historians who will read this an laugh at the old days when computers had just gigabytes.) The above server would cost about $2000 to build and only take 2U of space and use far less power than the 16 machines that are being replaced.

Note that I'm suggesting in this example only a 16 to 1 consolidation. Everyone has the same amount of ram. In reality the consolidation is many times higher because most of those using the Celerons are not using all the memory. Many are using only 1/5 of what they have and a lot of that is used by the individual kernels running. In OpenVZ there is one kernel for everyone.

Not also that many of these servers have idle time where the processor is doing nothing and they have lots of extra hard drive spave that isn't being used. By consolidating these systems the free resources are combined allowing you to run many more logical servers that each have more resources than the individual servers.

On a dedicated computer the user is stuck with an old slow 32 bit processor, a limited amount of ram, and an old slow hard drive with no backups. In a VPS that same user is running on a shared dual core 64 bit CPU sharing 8 gigs of ram with fast modern large hard drives with raid backup. That is a significant improvement over having their own dedicated box. So this is a better deal for the customer.

== Administration Advantages ==

If a customer needs you to fix something on their dedicated server you have to either know the root password or take the server down and boot from a rescue CD to get in and fix it. You also can't access the customer's files without logging in to their server as root. In a VPS you as host can enter their server at any time without a password. (Keeping the host environment very secure of course.) That allows you to do maintenance without having to look up the person's root password.

== Ease of Setup ==

Setup couldn't be easier as compared to building a dedicated server. All you have to do is type a few command and the new virtual server is ready to go. You can have the customer running while you are still on the phone taking the order. A dedicated box requires setup, installation, and often has to be scheduled. This involves cost and time. VPS is read instantly and easily. Any distro you want with all the latest updates installed. When a customer places an order they want it now. With VPS you can deliver it now.

== Backup Advantages ==

Additionally you can access the customers files directly from the host environment. This allows you to run rsync scripts to back up all the virtual servers to external storage or backup servers without the customer being aware that you are doing sophisticated backups. Then when the customer calls you up in a panic and says, "I totally screwed up my server and deleted a bunch of files by accident. Can you get it back?" You can magically restore their lost data and you are forever their hero.

== IP Allocation Advantages ==

Tired of allocating 4 IP addresses just to give the customer 1 usable? Or giving them 8 so they have 5 usable and them most of them only use one? How inefficient is that? With OpenVZ you can allocate IP addresses individually so that if a customer only needs one IP then they get only 1 IP. But if they need 9 IP addresses you can give them exactly 9 of them. They can call you up and say I need one more IP and you can give it to them in seconds. On a dedicated server if you gave them a /29 vlan and they are using all 5 IPs and they need another one - that is a huge hassle.

== Disk Space Allocation ==

On dedicated servers you have to install a big hard drive that is mostly wasted. If the customer wants backups then it's two hard drives. In OpenVZ you just allocate space in the raid array based on what the customer actually needs and they only use the space that they use rather than what's allocated. The "allocation" is really just a software limit and that is a line in a text file that you can instantly change the moment the customer needs more space. On a dedicatd box if the customer need a bigger drive then it's a trip to the data center with a new drive and a few hours time to copy everything over and replacing the drive, not to mention the down time.

== Memory Upgrades ==

Memory upgrades are as easy as hard drive upgrades. Juch one command that the user has more ram. But what if the server is full and you don't have any more ram? No problem. Just copy the user's VE (virtual environment) over to another physical server with rsync and start them up there. In only a few minutes you've migrated them to a new box and they are up and running.

== Migration ==

Suppose a customer just needs a bigger server. Migration is easy in the VPS environment because the VE is consistent between servers. You just copy over the files and start it up. You don't have to build a new server, install an OS, copy it all over, and then mess with it for an hour getting everything to work.

== Emergency Procedures ==

Let's say that a server fries. With VPS and good backups you have more options. You can copy the backup of the VPS onto abother server and restore it as of the last (nightly) backup. (I'm a backup freak - but it pays.) That gets the customers up instantly if they need that while a tech can go down there and fox the server with less pressure. This give you more options when bad things happen.

== Load Balancing ==

OpenVZ allows you to migrate servers live from one physical server to another. I haven't yet done that but I have done a shutdown, copy, and restart of the VE on another server and it's so easy to do that. So suppose you have a server that's a little crowded and some user starts hogging some resources. No problem. You just move a few users to another box and problem solved. This could probably be done automatically with some well configured cluster and I would love it if someone wrote a wiki page telling us how to do it.

== Protecting your Customers ==

Since you are managing the host system you can create IP filters and port blocking policies that help keep users from exploiting you or keep hackers from exploiting your users. Instead of a separate box that is all theirs you have them in a more managed shell allowing you to keep the inexperienced out of trouble. This provides them with a service that it watched more closely allowing them to do their own thing, but keeping you closer by to keep them out of trouble.

= Cost =

The cost savings are rather obvious. An entire rack compressed into one or two computers. Picture the space and power savings. The greenhouse gas not being generated by the power you're not using. The number of computers that you are not buying. The hours you are saving in setup time and administrative time. When it comes to saving money this is definitely a winner. You can take that extra money and pass some on to customers and keep some extra for yourself.

= The Down Side =

Any time you add another layer then you have another layer of things that can go wrong. It takes some learning to understand the process and there is the possibility that one person can screw up the system for everyone. As virtualization develops it will get better. OpenVZ is very stable in that it is far less intrusive than other virtualization methods. It is limited to Linux only so BSD and Windows users will have to do something else.

= Conclusion =

I believe that VPS represents the future of computing. The space, power, and cost savings are too great to ignore. I see data centers that are massive clusters running tens of thousands of logical servers that transparently migrate around the physical resources and are up 100% of the time. Customers no longer will have to deal with issues of backups they way they have to now and it will simplify the hosting process. I think that every data center should be looking into virtualization technology now with the idea that you are going to be doing this and it's time to at least start thinking about it and exploring it with an eye towards the future.

I have to say that my view of VPS has radically changed and that I now see this as a solution not just for people wanting little servers but for most everyone who is looking for dedicated service. VPS is a different way of looking at the computing world and it takes some significant mental adjustment and education to grasp the big picture.

[[Category: Technology]]
[[Category: Concepts]]

VPS vs Dedicated

2007-02-02T16:45:33Z

Mperkel:

VPS vs Dedicated

2007-02-02T16:38:58Z

Mperkel: /* The Down Side */

Although I am somewhat of a new user to the VPS world I thought I'd write a short article giving an overview of why use VPS instead of dedicated servers for those of you who are involved in the hosting business or people thinking about leasing a VPS server. Here I will address misconceptions I had about VPS and talk about how my perspective on VPS is changing.

= Why use Virtual Private Servers instead of Dedicated Servers =

Like many of you when I first heard of the idea of VPS I pictured it is some small lame server that is sold to 12 year olds trying to start hosting companies on the cheap. It had never quite caught my attention until I decided I needed a remote name server and all I needed was enough of a server to run bind, but didn't want to by a dedicated box just to do that. So I got a VPS based on Virtuozzo for $80/year and it worked great.

In the process however I started understanding the VPS concept and it became apparent that this is more that just a tool to create little servers. The way I see it VPS can replace dedicated servers in many situations in a data center and do a better job than dedicated. You can actually give the customer more horsepower and better hosting than selling them a small dedicated box. (Of course big customers will still need their own server.)

I don't own a data center business myself but I have a friend who does and I colo several servers there. He has several racks of some old Celeron boxes with 512 mgs of ram and one or two 80 gig drives depending of if the customer has any concept of backups, which most of them don't. I'm looking at the racks of Celerons and P4s thinking that each rack could be consolidated into a single modern server and that the customers would actually have a better server than the one they are on now. And the cost saving is tremendous.

= Advantages of VPS =

Most small dedicated servers are a waste of resources. People buy bigger servers than they need and the excess capacity is wasted. These servers take both space an power which is expensive in a data center and you have hardware costs assiciated with each server that you have to recoup. People often don't do any backups so after several years the hard drive fails and they lose everything. And it's your fault for not backing them up in the first place.

Imagine a rack of 16 Celeron boxes with 80 gig drives being replaced by a Dual Core Athlox X2 with 8 gigs of ram and 4 500gb SATA 2 drives running in a raid 10 configuration. (Writing this in Feb of 2007 for future historians who will read this an laugh at the old days when computers had just gigabytes.) The above server would cost about $2000 to build and only take 2U of space and use far less power than the 16 machines that are being replaced.

Note that I'm suggesting in this example only a 16 to 1 consolidation. Everyone has the same amount of ram. In reality the consolidation is many times higher because most of those using the Celerons are not using all the memory. Many are using only 1/5 of what they have and a lot of that is used by the individual kernels running. In OpenVZ there is one kernel for everyone.

Not also that many of these servers have idle time where the processor is doing nothing and they have lots of extra hard drive spave that isn't being used. By consolidating these systems the free resources are combined allowing you to run many more logical servers that each have more resources than the individual servers.

On a dedicated computer the user is stuck with an old slow 32 bit processor, a limited amount of ram, and an old slow hard drive with no backups. In a VPS that same user is running on a shared dual core 64 bit CPU sharing 8 gigs of ram with fast modern large hard drives with raid backup. That is a significant improvement over having their own dedicated box. So this is a better deal for the customer.

== Administration Advantages ==

If a customer needs you to fix something on their dedicated server you have to either know the root password or take the server down and boot from a rescue CD to get in and fix it. You also can't access the customer's files without logging in to their server as root. In a VPS you as host can enter their server at any time without a password. (Keeping the host environment very secure of course.) That allows you to do maintenance without having to look up the person's root password.

== Ease of Setup ==

Setup couldn't be easier as compared to building a dedicated server. All you have to do is type a few command and the new virtual server is ready to go. You can have the customer running while you are still on the phone taking the order. A dedicated box requires setup, installation, and often has to be scheduled. This involves cost and time. VPS is read instantly and easily. Any distro you want with all the latest updates installed. When a customer places an order they want it now. With VPS you can deliver it now.

== Backup Advantages ==

Additionally you can access the customers files directly from the host environment. This allows you to run rsync scripts to back up all the virtual servers to external storage or backup servers without the customer being aware that you are doing sophisticated backups. Then when the customer calls you up in a panic and says, "I totally screwed up my server and deleted a bunch of files by accident. Can you get it back?" You can magically restore their lost data and you are forever their hero.

== IP Allocation Advantages ==

Tired of allocating 4 IP addresses just to give the customer 1 usable? Or giving them 8 so they have 5 usable and them most of them only use one? How inefficient is that? With OpenVZ you can allocate IP addresses individually so that if a customer only needs one IP then they get only 1 IP. But if they need 9 IP addresses you can give them exactly 9 of them. They can call you up and say I need one more IP and you can give it to them in seconds. On a dedicated server if you gave them a /29 vlan and they are using all 5 IPs and they need another one - that is a huge hassle.

== Disk Space Allocation ==

On dedicated servers you have to install a big hard drive that is mostly wasted. If the customer wants backups then it's two hard drives. In OpenVZ you just allocate space in the raid array based on what the customer actually needs and they only use the space that they use rather than what's allocated. The "allocation" is really just a software limit and that is a line in a text file that you can instantly change the moment the customer needs more space. On a dedicatd box if the customer need a bigger drive then it's a trip to the data center with a new drive and a few hours time to copy everything over and replacing the drive, not to mention the down time.

== Memory Upgrades ==

Memory upgrades are as easy as hard drive upgrades. Juch one command that the user has more ram. But what if the server is full and you don't have any more ram? No problem. Just copy the user's VE (virtual environment) over to another physical server with rsync and start them up there. In only a few minutes you've migrated them to a new box and they are up and running.

== Migration ==

Suppose a customer just needs a bigger server. Migration is easy in the VPS environment because the VE is consistent between servers. You just copy over the files and start it up. You don't have to build a new server, install an OS, copy it all over, and then mess with it for an hour getting everything to work.

== Emergency Procedures ==

Let's say that a server fries. With VPS and good backups you have more options. You can copy the backup of the VPS onto abother server and restore it as of the last (nightly) backup. (I'm a backup freak - but it pays.) That gets the customers up instantly if they need that while a tech can go down there and fox the server with less pressure. This give you more options when bad things happen.

== Load Balancing ==

OpenVZ allows you to migrate servers live from one physical server to another. I haven't yet done that but I have done a shutdown, copy, and restart of the VE on another server and it's so easy to do that. So suppose you have a server that's a little crowded and some user starts hogging some resources. No problem. You just move a few users to another box and problem solved. This could probably be done automatically with some well configured cluster and I would love it if someone wrote a wiki page telling us how to do it.

== Protecting your Customers ==

Since you are managing the host system you can create IP filters and port blocking policies that help keep users from exploiting you or keep hackers from exploiting your users. Instead of a separate box that is all theirs you have them in a more managed shell allowing you to keep the inexperienced out of trouble. This provides them with a service that it watched more closely allowing them to do their own thing, but keeping you closer by to keep them out of trouble.

= Cost =

The cost savings are rather obvious. An entire rack compressed into one or two computers. Picture the space and power savings. The greenhouse gas not being generated by the power you're not using. The number of computers that you are not buying. The hours you are saving in setup time and administrative time. When it comes to saving money this is definitely a winner. You can take that extra money and pass some on to customers and keep some extra for yourself.

= The Down Side =

Any time you add another layer then you have another layer of things that can go wrong. It takes some learning to understand the process and there is the possibility that one person can screw up the system for everyone. As virtualization develops it will get better. OpenVZ is very stable in that it is far less intrusive than other virtualization methods. It is limited to Linux only so BSD and Windows users will have to do something else.

= Conclusion =

I believe that VPS represents the future of computing. The space, power, and cost savings are too great to ignore. I see data centers that are massive clusters running tens of thousands of logical servers that transparently migrate around the physical resources and are up 100% of the time. Customers no longer will have to deal with issues of backups they way they have to now and it will simplify the hosting process. I think that every data center should be looking into virtualization technology now with the idea that you are going to be doing this and it's time to at least start thinking about it and exploring it with an eye towards the future.

I have to say that my view of VPS has radically changed and that I now see this as a solution not just for people wanting little servers but for most everyone who is looking for dedicated service. VPS is a different way of looking at the computing world and it takes some significant mental adjustment and education to grasp the big picture.

VPS vs Dedicated

2007-02-02T16:29:54Z

Mperkel: /* Backup Advantages */

Although I am somewhat of a new user to the VPS world I thought I'd write a short article giving an overview of why use VPS instead of dedicated servers for those of you who are involved in the hosting business or people thinking about leasing a VPS server. Here I will address misconceptions I had about VPS and talk about how my perspective on VPS is changing.

= Why use Virtual Private Servers instead of Dedicated Servers =

Like many of you when I first heard of the idea of VPS I pictured it is some small lame server that is sold to 12 year olds trying to start hosting companies on the cheap. It had never quite caught my attention until I decided I needed a remote name server and all I needed was enough of a server to run bind, but didn't want to by a dedicated box just to do that. So I got a VPS based on Virtuozzo for $80/year and it worked great.

In the process however I started understanding the VPS concept and it became apparent that this is more that just a tool to create little servers. The way I see it VPS can replace dedicated servers in many situations in a data center and do a better job than dedicated. You can actually give the customer more horsepower and better hosting than selling them a small dedicated box. (Of course big customers will still need their own server.)

I don't own a data center business myself but I have a friend who does and I colo several servers there. He has several racks of some old Celeron boxes with 512 mgs of ram and one or two 80 gig drives depending of if the customer has any concept of backups, which most of them don't. I'm looking at the racks of Celerons and P4s thinking that each rack could be consolidated into a single modern server and that the customers would actually have a better server than the one they are on now. And the cost saving is tremendous.

= Advantages of VPS =

Most small dedicated servers are a waste of resources. People buy bigger servers than they need and the excess capacity is wasted. These servers take both space an power which is expensive in a data center and you have hardware costs assiciated with each server that you have to recoup. People often don't do any backups so after several years the hard drive fails and they lose everything. And it's your fault for not backing them up in the first place.

Imagine a rack of 16 Celeron boxes with 80 gig drives being replaced by a Dual Core Athlox X2 with 8 gigs of ram and 4 500gb SATA 2 drives running in a raid 10 configuration. (Writing this in Feb of 2007 for future historians who will read this an laugh at the old days when computers had just gigabytes.) The above server would cost about $2000 to build and only take 2U of space and use far less power than the 16 machines that are being replaced.

Note that I'm suggesting in this example only a 16 to 1 consolidation. Everyone has the same amount of ram. In reality the consolidation is many times higher because most of those using the Celerons are not using all the memory. Many are using only 1/5 of what they have and a lot of that is used by the individual kernels running. In OpenVZ there is one kernel for everyone.

Not also that many of these servers have idle time where the processor is doing nothing and they have lots of extra hard drive spave that isn't being used. By consolidating these systems the free resources are combined allowing you to run many more logical servers that each have more resources than the individual servers.

On a dedicated computer the user is stuck with an old slow 32 bit processor, a limited amount of ram, and an old slow hard drive with no backups. In a VPS that same user is running on a shared dual core 64 bit CPU sharing 8 gigs of ram with fast modern large hard drives with raid backup. That is a significant improvement over having their own dedicated box. So this is a better deal for the customer.

== Administration Advantages ==

If a customer needs you to fix something on their dedicated server you have to either know the root password or take the server down and boot from a rescue CD to get in and fix it. You also can't access the customer's files without logging in to their server as root. In a VPS you as host can enter their server at any time without a password. (Keeping the host environment very secure of course.) That allows you to do maintenance without having to look up the person's root password.

== Ease of Setup ==

Setup couldn't be easier as compared to building a dedicated server. All you have to do is type a few command and the new virtual server is ready to go. You can have the customer running while you are still on the phone taking the order. A dedicated box requires setup, installation, and often has to be scheduled. This involves cost and time. VPS is read instantly and easily. Any distro you want with all the latest updates installed. When a customer places an order they want it now. With VPS you can deliver it now.

== Backup Advantages ==

Additionally you can access the customers files directly from the host environment. This allows you to run rsync scripts to back up all the virtual servers to external storage or backup servers without the customer being aware that you are doing sophisticated backups. Then when the customer calls you up in a panic and says, "I totally screwed up my server and deleted a bunch of files by accident. Can you get it back?" You can magically restore their lost data and you are forever their hero.

== IP Allocation Advantages ==

Tired of allocating 4 IP addresses just to give the customer 1 usable? Or giving them 8 so they have 5 usable and them most of them only use one? How inefficient is that? With OpenVZ you can allocate IP addresses individually so that if a customer only needs one IP then they get only 1 IP. But if they need 9 IP addresses you can give them exactly 9 of them. They can call you up and say I need one more IP and you can give it to them in seconds. On a dedicated server if you gave them a /29 vlan and they are using all 5 IPs and they need another one - that is a huge hassle.

== Disk Space Allocation ==

On dedicated servers you have to install a big hard drive that is mostly wasted. If the customer wants backups then it's two hard drives. In OpenVZ you just allocate space in the raid array based on what the customer actually needs and they only use the space that they use rather than what's allocated. The "allocation" is really just a software limit and that is a line in a text file that you can instantly change the moment the customer needs more space. On a dedicatd box if the customer need a bigger drive then it's a trip to the data center with a new drive and a few hours time to copy everything over and replacing the drive, not to mention the down time.

== Memory Upgrades ==

Memory upgrades are as easy as hard drive upgrades. Juch one command that the user has more ram. But what if the server is full and you don't have any more ram? No problem. Just copy the user's VE (virtual environment) over to another physical server with rsync and start them up there. In only a few minutes you've migrated them to a new box and they are up and running.

== Migration ==

Suppose a customer just needs a bigger server. Migration is easy in the VPS environment because the VE is consistent between servers. You just copy over the files and start it up. You don't have to build a new server, install an OS, copy it all over, and then mess with it for an hour getting everything to work.

== Emergency Procedures ==

Let's say that a server fries. With VPS and good backups you have more options. You can copy the backup of the VPS onto abother server and restore it as of the last (nightly) backup. (I'm a backup freak - but it pays.) That gets the customers up instantly if they need that while a tech can go down there and fox the server with less pressure. This give you more options when bad things happen.

== Load Balancing ==

OpenVZ allows you to migrate servers live from one physical server to another. I haven't yet done that but I have done a shutdown, copy, and restart of the VE on another server and it's so easy to do that. So suppose you have a server that's a little crowded and some user starts hogging some resources. No problem. You just move a few users to another box and problem solved. This could probably be done automatically with some well configured cluster and I would love it if someone wrote a wiki page telling us how to do it.

== Protecting your Customers ==

Since you are managing the host system you can create IP filters and port blocking policies that help keep users from exploiting you or keep hackers from exploiting your users. Instead of a separate box that is all theirs you have them in a more managed shell allowing you to keep the inexperienced out of trouble. This provides them with a service that it watched more closely allowing them to do their own thing, but keeping you closer by to keep them out of trouble.

= Cost =

The cost savings are rather obvious. An entire rack compressed into one or two computers. Picture the space and power savings. The greenhouse gas not being generated by the power you're not using. The number of computers that you are not buying. The hours you are saving in setup time and administrative time. When it comes to saving money this is definitely a winner. You can take that extra money and pass some on to customers and keep some extra for yourself.

= The Down Side =

Any time you add another layer then you have another layer of things that can go wrong. It takes some learning to understand the process and there is the possibility that one person can screw up the system for everyone. As virtualization develops it will get better. OpenVZ is very stable in that it is far less intrusive than other virtualization methods. It is limited to Linux only so BSD and Windows users will have to do something else.

VPS vs Dedicated

2007-02-02T16:24:35Z

Mperkel: /* Cost */

Although I am somewhat of a new user to the VPS world I thought I'd write a short article giving an overview of why use VPS instead of dedicated servers for those of you who are involved in the hosting business or people thinking about leasing a VPS server. Here I will address misconceptions I had about VPS and talk about how my perspective on VPS is changing.

= Why use Virtual Private Servers instead of Dedicated Servers =

Like many of you when I first heard of the idea of VPS I pictured it is some small lame server that is sold to 12 year olds trying to start hosting companies on the cheap. It had never quite caught my attention until I decided I needed a remote name server and all I needed was enough of a server to run bind, but didn't want to by a dedicated box just to do that. So I got a VPS based on Virtuozzo for $80/year and it worked great.

In the process however I started understanding the VPS concept and it became apparent that this is more that just a tool to create little servers. The way I see it VPS can replace dedicated servers in many situations in a data center and do a better job than dedicated. You can actually give the customer more horsepower and better hosting than selling them a small dedicated box. (Of course big customers will still need their own server.)

I don't own a data center business myself but I have a friend who does and I colo several servers there. He has several racks of some old Celeron boxes with 512 mgs of ram and one or two 80 gig drives depending of if the customer has any concept of backups, which most of them don't. I'm looking at the racks of Celerons and P4s thinking that each rack could be consolidated into a single modern server and that the customers would actually have a better server than the one they are on now. And the cost saving is tremendous.

= Advantages of VPS =

Most small dedicated servers are a waste of resources. People buy bigger servers than they need and the excess capacity is wasted. These servers take both space an power which is expensive in a data center and you have hardware costs assiciated with each server that you have to recoup. People often don't do any backups so after several years the hard drive fails and they lose everything. And it's your fault for not backing them up in the first place.

Imagine a rack of 16 Celeron boxes with 80 gig drives being replaced by a Dual Core Athlox X2 with 8 gigs of ram and 4 500gb SATA 2 drives running in a raid 10 configuration. (Writing this in Feb of 2007 for future historians who will read this an laugh at the old days when computers had just gigabytes.) The above server would cost about $2000 to build and only take 2U of space and use far less power than the 16 machines that are being replaced.

Note that I'm suggesting in this example only a 16 to 1 consolidation. Everyone has the same amount of ram. In reality the consolidation is many times higher because most of those using the Celerons are not using all the memory. Many are using only 1/5 of what they have and a lot of that is used by the individual kernels running. In OpenVZ there is one kernel for everyone.

Not also that many of these servers have idle time where the processor is doing nothing and they have lots of extra hard drive spave that isn't being used. By consolidating these systems the free resources are combined allowing you to run many more logical servers that each have more resources than the individual servers.

On a dedicated computer the user is stuck with an old slow 32 bit processor, a limited amount of ram, and an old slow hard drive with no backups. In a VPS that same user is running on a shared dual core 64 bit CPU sharing 8 gigs of ram with fast modern large hard drives with raid backup. That is a significant improvement over having their own dedicated box. So this is a better deal for the customer.

== Administration Advantages ==

If a customer needs you to fix something on their dedicated server you have to either know the root password or take the server down and boot from a rescue CD to get in and fix it. You also can't access the customer's files without logging in to their server as root. In a VPS you as host can enter their server at any time without a password. (Keeping the host environment very secure of course.) That allows you to do maintenance without having to look up the person's root password.

== Backup Advantages ==

Additionally you can access the customers files directly from the host environment. This allows you to run rsync scripts to back up all the virtual servers to external storage or backup servers without the customer being aware that you are doing sophisticated backups. Then when the customer calls you up in a panic and says, "I totally screwed up my server and deleted a bunch of files by accident. Can you get it back?" You can magically restore their lost data and you are forever their hero.

== IP Allocation Advantages ==

Tired of allocating 4 IP addresses just to give the customer 1 usable? Or giving them 8 so they have 5 usable and them most of them only use one? How inefficient is that? With OpenVZ you can allocate IP addresses individually so that if a customer only needs one IP then they get only 1 IP. But if they need 9 IP addresses you can give them exactly 9 of them. They can call you up and say I need one more IP and you can give it to them in seconds. On a dedicated server if you gave them a /29 vlan and they are using all 5 IPs and they need another one - that is a huge hassle.

== Disk Space Allocation ==

On dedicated servers you have to install a big hard drive that is mostly wasted. If the customer wants backups then it's two hard drives. In OpenVZ you just allocate space in the raid array based on what the customer actually needs and they only use the space that they use rather than what's allocated. The "allocation" is really just a software limit and that is a line in a text file that you can instantly change the moment the customer needs more space. On a dedicatd box if the customer need a bigger drive then it's a trip to the data center with a new drive and a few hours time to copy everything over and replacing the drive, not to mention the down time.

== Memory Upgrades ==

Memory upgrades are as easy as hard drive upgrades. Juch one command that the user has more ram. But what if the server is full and you don't have any more ram? No problem. Just copy the user's VE (virtual environment) over to another physical server with rsync and start them up there. In only a few minutes you've migrated them to a new box and they are up and running.

== Migration ==

Suppose a customer just needs a bigger server. Migration is easy in the VPS environment because the VE is consistent between servers. You just copy over the files and start it up. You don't have to build a new server, install an OS, copy it all over, and then mess with it for an hour getting everything to work.

== Emergency Procedures ==

Let's say that a server fries. With VPS and good backups you have more options. You can copy the backup of the VPS onto abother server and restore it as of the last (nightly) backup. (I'm a backup freak - but it pays.) That gets the customers up instantly if they need that while a tech can go down there and fox the server with less pressure. This give you more options when bad things happen.

== Load Balancing ==

OpenVZ allows you to migrate servers live from one physical server to another. I haven't yet done that but I have done a shutdown, copy, and restart of the VE on another server and it's so easy to do that. So suppose you have a server that's a little crowded and some user starts hogging some resources. No problem. You just move a few users to another box and problem solved. This could probably be done automatically with some well configured cluster and I would love it if someone wrote a wiki page telling us how to do it.

== Protecting your Customers ==

Since you are managing the host system you can create IP filters and port blocking policies that help keep users from exploiting you or keep hackers from exploiting your users. Instead of a separate box that is all theirs you have them in a more managed shell allowing you to keep the inexperienced out of trouble. This provides them with a service that it watched more closely allowing them to do their own thing, but keeping you closer by to keep them out of trouble.

= Cost =

The cost savings are rather obvious. An entire rack compressed into one or two computers. Picture the space and power savings. The greenhouse gas not being generated by the power you're not using. The number of computers that you are not buying. The hours you are saving in setup time and administrative time. When it comes to saving money this is definitely a winner. You can take that extra money and pass some on to customers and keep some extra for yourself.

= The Down Side =

Any time you add another layer then you have another layer of things that can go wrong. It takes some learning to understand the process and there is the possibility that one person can screw up the system for everyone. As virtualization develops it will get better. OpenVZ is very stable in that it is far less intrusive than other virtualization methods. It is limited to Linux only so BSD and Windows users will have to do something else.

VPS vs Dedicated

2007-02-02T16:17:52Z

Mperkel: /* Load Balancing */

Although I am somewhat of a new user to the VPS world I thought I'd write a short article giving an overview of why use VPS instead of dedicated servers for those of you who are involved in the hosting business or people thinking about leasing a VPS server. Here I will address misconceptions I had about VPS and talk about how my perspective on VPS is changing.

= Why use Virtual Private Servers instead of Dedicated Servers =

Like many of you when I first heard of the idea of VPS I pictured it is some small lame server that is sold to 12 year olds trying to start hosting companies on the cheap. It had never quite caught my attention until I decided I needed a remote name server and all I needed was enough of a server to run bind, but didn't want to by a dedicated box just to do that. So I got a VPS based on Virtuozzo for $80/year and it worked great.

In the process however I started understanding the VPS concept and it became apparent that this is more that just a tool to create little servers. The way I see it VPS can replace dedicated servers in many situations in a data center and do a better job than dedicated. You can actually give the customer more horsepower and better hosting than selling them a small dedicated box. (Of course big customers will still need their own server.)

I don't own a data center business myself but I have a friend who does and I colo several servers there. He has several racks of some old Celeron boxes with 512 mgs of ram and one or two 80 gig drives depending of if the customer has any concept of backups, which most of them don't. I'm looking at the racks of Celerons and P4s thinking that each rack could be consolidated into a single modern server and that the customers would actually have a better server than the one they are on now. And the cost saving is tremendous.

= Advantages of VPS =

Most small dedicated servers are a waste of resources. People buy bigger servers than they need and the excess capacity is wasted. These servers take both space an power which is expensive in a data center and you have hardware costs assiciated with each server that you have to recoup. People often don't do any backups so after several years the hard drive fails and they lose everything. And it's your fault for not backing them up in the first place.

Imagine a rack of 16 Celeron boxes with 80 gig drives being replaced by a Dual Core Athlox X2 with 8 gigs of ram and 4 500gb SATA 2 drives running in a raid 10 configuration. (Writing this in Feb of 2007 for future historians who will read this an laugh at the old days when computers had just gigabytes.) The above server would cost about $2000 to build and only take 2U of space and use far less power than the 16 machines that are being replaced.

Note that I'm suggesting in this example only a 16 to 1 consolidation. Everyone has the same amount of ram. In reality the consolidation is many times higher because most of those using the Celerons are not using all the memory. Many are using only 1/5 of what they have and a lot of that is used by the individual kernels running. In OpenVZ there is one kernel for everyone.

Not also that many of these servers have idle time where the processor is doing nothing and they have lots of extra hard drive spave that isn't being used. By consolidating these systems the free resources are combined allowing you to run many more logical servers that each have more resources than the individual servers.

On a dedicated computer the user is stuck with an old slow 32 bit processor, a limited amount of ram, and an old slow hard drive with no backups. In a VPS that same user is running on a shared dual core 64 bit CPU sharing 8 gigs of ram with fast modern large hard drives with raid backup. That is a significant improvement over having their own dedicated box. So this is a better deal for the customer.

== Administration Advantages ==

If a customer needs you to fix something on their dedicated server you have to either know the root password or take the server down and boot from a rescue CD to get in and fix it. You also can't access the customer's files without logging in to their server as root. In a VPS you as host can enter their server at any time without a password. (Keeping the host environment very secure of course.) That allows you to do maintenance without having to look up the person's root password.

== Backup Advantages ==

Additionally you can access the customers files directly from the host environment. This allows you to run rsync scripts to back up all the virtual servers to external storage or backup servers without the customer being aware that you are doing sophisticated backups. Then when the customer calls you up in a panic and says, "I totally screwed up my server and deleted a bunch of files by accident. Can you get it back?" You can magically restore their lost data and you are forever their hero.

== IP Allocation Advantages ==

Tired of allocating 4 IP addresses just to give the customer 1 usable? Or giving them 8 so they have 5 usable and them most of them only use one? How inefficient is that? With OpenVZ you can allocate IP addresses individually so that if a customer only needs one IP then they get only 1 IP. But if they need 9 IP addresses you can give them exactly 9 of them. They can call you up and say I need one more IP and you can give it to them in seconds. On a dedicated server if you gave them a /29 vlan and they are using all 5 IPs and they need another one - that is a huge hassle.

== Disk Space Allocation ==

On dedicated servers you have to install a big hard drive that is mostly wasted. If the customer wants backups then it's two hard drives. In OpenVZ you just allocate space in the raid array based on what the customer actually needs and they only use the space that they use rather than what's allocated. The "allocation" is really just a software limit and that is a line in a text file that you can instantly change the moment the customer needs more space. On a dedicatd box if the customer need a bigger drive then it's a trip to the data center with a new drive and a few hours time to copy everything over and replacing the drive, not to mention the down time.

== Memory Upgrades ==

Memory upgrades are as easy as hard drive upgrades. Juch one command that the user has more ram. But what if the server is full and you don't have any more ram? No problem. Just copy the user's VE (virtual environment) over to another physical server with rsync and start them up there. In only a few minutes you've migrated them to a new box and they are up and running.

== Migration ==

Suppose a customer just needs a bigger server. Migration is easy in the VPS environment because the VE is consistent between servers. You just copy over the files and start it up. You don't have to build a new server, install an OS, copy it all over, and then mess with it for an hour getting everything to work.

== Emergency Procedures ==

Let's say that a server fries. With VPS and good backups you have more options. You can copy the backup of the VPS onto abother server and restore it as of the last (nightly) backup. (I'm a backup freak - but it pays.) That gets the customers up instantly if they need that while a tech can go down there and fox the server with less pressure. This give you more options when bad things happen.

== Load Balancing ==

OpenVZ allows you to migrate servers live from one physical server to another. I haven't yet done that but I have done a shutdown, copy, and restart of the VE on another server and it's so easy to do that. So suppose you have a server that's a little crowded and some user starts hogging some resources. No problem. You just move a few users to another box and problem solved. This could probably be done automatically with some well configured cluster and I would love it if someone wrote a wiki page telling us how to do it.

== Protecting your Customers ==

Since you are managing the host system you can create IP filters and port blocking policies that help keep users from exploiting you or keep hackers from exploiting your users. Instead of a separate box that is all theirs you have them in a more managed shell allowing you to keep the inexperienced out of trouble. This provides them with a service that it watched more closely allowing them to do their own thing, but keeping you closer by to keep them out of trouble.

= Cost =

The cost savings are rather obvious. An entire rack compressed into one or two computers. Picture the space and power savings. The greenhouse gasses not being generated by the power you're not using. The number of computers that you are not buying. The hours you are saving in setup time and administrative time. When it comes to saving money this is definitely a winner. You can take that extra money and pass some on to customers and keep some extra for yourself.

VPS vs Dedicated

2007-02-02T16:07:24Z

Mperkel: /* Migration */

VPS vs Dedicated

2007-02-02T15:51:44Z

Mperkel: /* IP Allocation Advantages */

VPS vs Dedicated

2007-02-02T15:40:04Z

Mperkel: /* Administration Advantages */

VPS vs Dedicated

2007-02-02T15:25:00Z

Mperkel: /* Advantages of VPS */

VPS vs Dedicated

2007-02-02T15:24:22Z

Mperkel: /* Why use Virtual Private Servers instead of Dedicated Servers */

VPS vs Dedicated

2007-02-02T15:24:04Z

Mperkel: /* Advantages of VPS */

VPS vs Dedicated

2007-02-02T15:04:15Z

Mperkel: /* Why use Virtual Private Servers instead of Dedicated Servers */

VPS vs Dedicated

2007-02-02T14:56:56Z

Mperkel:

VPS vs Dedicated

2007-02-02T14:51:03Z

Mperkel:

- Why use Virtual Private Servers instead of Dedicated Servers? -

Like many of you when I first heard of the idea of VPS I pictured it is some small lame server that is sold to 12 year olds trying to start hosting companies on the cheap. It had never quite caught my attention until I decided I needed a remote name server and all I needed was enough of a server to run bind, but didn't want to by a dedicated box just to do that. So I got a VPS based on Virtuozzo for $80/year and it worked great.

In the process however I started understanding the VPS concept and it became apparent that this is more that just a tool to create little servers. The way I see it VPS can replace dedicated servers in many situations in a data center and do a better job than dedicated. You can actually give the customer more horsepower and better hosting than selling them a small dedicated box. (Of course big customers will still need their own server.)