OpenVZ Virtuozzo Containers Wiki - User contributions [en]

Monitoring openvz resources using munin

2007-06-25T01:37:37Z

Alexkuklin:

== munin plugin ==

The plugin listed below grabs all the bean counters' values.

<pre>#!/bin/sh
#
# plugin to monitor OpenVZ bean counters.
#
#
#%# family=auto
#%# capabilities=autoconf suggest

ATTR=`basename $0 | sed 's/^vebc_//g'`

if [ "$1" = "autoconf" ]; then
if [ -r /proc/bc/0/resources ]; then
echo yes
exit 0
else
echo "no (/proc/bc/0/resources not found)"
exit 1
fi
fi

if [ "$1" = "suggest" ]; then

if [ -r /proc/bc/0/resources ]; then
cat /proc/bc/0/resources |
while read str; do

vals=($str)
echo ${vals[0]}
done

exit 0
else
exit 1
fi
fi

if [ "$1" = "config" ]; then

# echo "graph_order down up"
echo "graph_title $ATTR beancounter for VE's"
echo 'graph_category system'
echo "graph_info 'VE bean counters info'"

for VEID in `ls -d1 /proc/bc/???`; do
id=`basename $VEID`
grep $ATTR $VEID/resources |
while read str; do

vals=($str)
name=${vals[0]}
echo ${id}.label $id
echo "${id}.warning ${vals[3]}"
echo "${id}.critical ${vals[4]}"
done
done

exit 0
fi;

for VEID in `ls -d1 /proc/bc/???`; do
id=`basename $VEID`
grep $ATTR $VEID/resources |
while read str; do

vals=($str)
name=${vals[0]}
echo "$id.value ${vals[1]}"
done
done

</pre>

Please note, you have to configure plugin to run as root:

<code>
[vebc*]
user root
</code>

at /etc/munin/plugin-conf.d/ somewhere.

Monitoring openvz resources using munin

2007-06-25T01:37:08Z

Alexkuklin:

== munin plugin ==

The plugin listed below grabs all the bean counters' values.

[[#!/bin/sh
#
# plugin to monitor OpenVZ bean counters.
#
#
#%# family=auto
#%# capabilities=autoconf suggest

ATTR=`basename $0 | sed 's/^vebc_//g'`

if [ "$1" = "autoconf" ]; then
if [ -r /proc/bc/0/resources ]; then
echo yes
exit 0
else
echo "no (/proc/bc/0/resources not found)"
exit 1
fi
fi

if [ "$1" = "suggest" ]; then

if [ -r /proc/bc/0/resources ]; then
cat /proc/bc/0/resources |
while read str; do

vals=($str)
echo ${vals[0]}
done

exit 0
else
exit 1
fi
fi

if [ "$1" = "config" ]; then

# echo "graph_order down up"
echo "graph_title $ATTR beancounter for VE's"
echo 'graph_category system'
echo "graph_info 'VE bean counters info'"

for VEID in `ls -d1 /proc/bc/???`; do
id=`basename $VEID`
grep $ATTR $VEID/resources |
while read str; do

vals=($str)
name=${vals[0]}
echo ${id}.label $id
echo "${id}.warning ${vals[3]}"
echo "${id}.critical ${vals[4]}"
done
done

exit 0
fi;

for VEID in `ls -d1 /proc/bc/???`; do
id=`basename $VEID`
grep $ATTR $VEID/resources |
while read str; do

vals=($str)
name=${vals[0]}
echo "$id.value ${vals[1]}"
done
done

]]

Please note, you have to configure plugin to run as root:

<code>
[vebc*]
user root
</code>

at /etc/munin/plugin-conf.d/ somewhere.

Monitoring openvz resources using munin

2007-06-25T01:36:47Z

Alexkuklin:

== munin plugin ==

The plugin listed below grabs all the bean counters' values.

{{#!/bin/sh
#
# plugin to monitor OpenVZ bean counters.
#
#
#%# family=auto
#%# capabilities=autoconf suggest

ATTR=`basename $0 | sed 's/^vebc_//g'`

if [ "$1" = "autoconf" ]; then
if [ -r /proc/bc/0/resources ]; then
echo yes
exit 0
else
echo "no (/proc/bc/0/resources not found)"
exit 1
fi
fi

if [ "$1" = "suggest" ]; then

if [ -r /proc/bc/0/resources ]; then
cat /proc/bc/0/resources |
while read str; do

vals=($str)
echo ${vals[0]}
done

exit 0
else
exit 1
fi
fi

if [ "$1" = "config" ]; then

# echo "graph_order down up"
echo "graph_title $ATTR beancounter for VE's"
echo 'graph_category system'
echo "graph_info 'VE bean counters info'"

for VEID in `ls -d1 /proc/bc/???`; do
id=`basename $VEID`
grep $ATTR $VEID/resources |
while read str; do

vals=($str)
name=${vals[0]}
echo ${id}.label $id
echo "${id}.warning ${vals[3]}"
echo "${id}.critical ${vals[4]}"
done
done

exit 0
fi;

for VEID in `ls -d1 /proc/bc/???`; do
id=`basename $VEID`
grep $ATTR $VEID/resources |
while read str; do

vals=($str)
name=${vals[0]}
echo "$id.value ${vals[1]}"
done
done

}}

Please note, you have to configure plugin to run as root:

<code>
[vebc*]
user root
</code>

at /etc/munin/plugin-conf.d/ somewhere.

Monitoring openvz resources using munin

2007-06-25T01:34:47Z

Alexkuklin: New page: == munin plugin == The plugin listed below grabs all the bean counters' values. Please note, you have to configure plugin to run as root: <code> [vebc*] user root </code> at /etc/mun...

== munin plugin ==

The plugin listed below grabs all the bean counters' values.

Please note, you have to configure plugin to run as root:

<code>
[vebc*]
user root
</code>

at /etc/munin/plugin-conf.d/ somewhere.

Physical to container

2007-03-23T12:21:00Z

Alexkuklin: /* Setting VE parameters */

A rough description of how to migrate existing physical server into a [[VE]].

== Prepare a new “empty” VE ==
For OpenVZ this would mean the following (assume you chose VE ID of 123):

mkdir /vz/root/123 /vz/private/123
cat /etc/vz/conf/ve-vps.basic.conf-sample > /etc/vz/conf/123.conf

== Preparing to migrate ==

Stop most services on a machine to be migrated. “Most” means services such as web server, databases and the like — so you will not loose your data. Just leave the bare minimum (including ssh daemon).

== Copying the data ==

Copy all your data from the machine to an OpenVZ box. Say you'll be using VE with ID of 123, then all the data should be placed to <code>/vz/private/123/</code> directory (so there will be directories such as <code>/vz/private/123/bin</code>, <code>etc</code>, <code>var</code> and so on). This could be done in several ways:

=== rsync ===
rsync example (run from the new HN):
rsync -arvpz --numeric-ids --exclude dev --exclude proc --exclude tmp -e "ssh -l root@a.b.c.d" root@a.b.c.d:/ /vz/private/123/

'''Advantage:''' Your system doesn't really go down.

=== Live CD ===
Another way to do is using a live cd, booting up and use tar to dump the complete disk in a tar you save over the network or on a USB device.

=== Tar ===
Another approach is using tar and excluding some dirs, you could do it like this:

Create a file /tmp/excludes.excl with these contents:
.bash_history
/dev/*
/mnt/*
/tmp/*
/proc/*
/sys/*
/usr/src/*

Then create the tar. But remember, when the system is 'not' using udev, you have to look into /proc/ after creating your VE because some devices might not exist. (/dev/ptmx or others)

# tar cjpf /tmp/mysystem.tar.bz2 / -X /tmp/excludes.excl

Naturally, you can only do this when the critical services (MySQL, apache, ..) are stopped and your /tmp filesystem is big enough to contain your tar.

'''Advantage:''' You don't need to boot from a livecd, so your system doesn't really go down.

== Setting VE parameters ==

=== OSTEMPLATE ===
You have to add <code>OSTEMPLATE=xxx</code> line to <code>/etc/vz/conf/123.conf</code> file, where <code>xxx</code> would be distribution name (like <code>debian-3.0</code>) for vzctl to be able to make changes specific for this distribution.

=== IP address(es) ===
Also, you have to supply an IP for a new VE:

vzctl set 123 --ipadd x.x.x.x --save

=== venet vs. veth ===
You may use veth interface instead of venet if you need just bring old server up for seamless migration of services.
It may be nessessary if server you are migrating is badly configured and it is hard to find all hard-coded net interfaces settings and so on.

veth inteface may me included into bridge to allow seamless old installation access.

== Making adjustments ==
Since VE is a bit different than a real physical server, you have to edit some files inside your new VE.

=== /etc/inittab ===
A VE does not have real ttys, so you have to disable getty in <code>/etc/inittab</code> (i. e. <code>/vz/private/123/etc/inittab</code>).

sed -i -e '/getty/d' /vz/private/123/etc/inittab

=== /etc/mtab ===
Link <code>/etc/mtab</code> to <code>/proc/mounts</code>:

rm -f /vz/private/123/etc/mtab
ln -s /proc/mounts /vz/private/123/etc/mtab

=== /etc/fstab ===
Since you do not have any real disk partitions in a VE, /etc/fstab (or most part of it) is no longer needed. Empty it (excluding the line for /dev/pts):

cp /vz/private/123/etc/fstab /vz/private/123/etc/fstab.old
grep devpts /vz/private/123/etc/fstab.old > /vz/private/123/etc/fstab

You can also mount a devpts in a running (but not fully functional) VE:
vzctl exec 123 mount -t devpts none /dev/pts

=== /dev TTY devices ===
In order for vzctl enter to work, a VE need to have some entries in /dev. This can either be /dev/ttyp* and /dev/ptyp*, or /dev/ptmx and mounted /dev/pts.

==== /dev/ptmx ====
Check that /dev/ptmx exists. If it does not, create with:
mknod /vz/private/123/dev/ptmx c 5 2

==== /dev/pts/ ====
Check that /dev/pts exists. It's a directory, if it does not exist, create with:
mkdir /vz/private/123/dev/pts

==== /dev/ttyp* and /dev/ptyp* ====
Check that /dev/ttyp* and /dev/ptyp* files are there. If not, you have to create those, either by using /sbin/MAKEDEV, or by copying them from the host system.

To copy:
cp -a /dev/ttyp* /dev/ptyp* /vz/private/123/dev/

To recreate with MAKEDEV, either
/sbin/MAKEDEV -d /vz/private/123/dev ttyp ptyp
or
cd /vz/private/123/dev && /sbin/MAKEDEV ttyp

=== Other devices ===

==== /dev/urandom ====
Check that /dev/urandom exists. If it does not, create with:
mknod /vz/private/123/dev/urandom c 1 9

=== /etc/init.d services ===

Some system services can (or in some cases should) be disabled. A few good candidates are:

* acpid, amd (not needed)
* checkfs, checkroot (no filesystem checking is required in VE)
* clock (no clock setting is required/allowed in VE)
* consolefont (VE does not have a console)
* hdparm (VE does not have real hard drives)
* klogd (unless you use iptables to LOG some packets)
* keymaps (VE does not have a real keyboard)
* kudzu (VE does not have real hardware)
* lm_sensors (VE does not have access to hardware sensors)
* microcodectl (VE can not update CPU microcode)
* netplugd (VE does not have real Ethernet device)

To see which services are enabled:
* RedHat/Fedora/SUSE: <code>/sbin/chkconfig --list</code>
* Debian: <code>*FIXME*</code>
* Gentoo: <code>/sbin/rc-update show</code>

To disable the service:
* RedHat/Fedora/SUSE: <code>/sbin/chkconfig --del SERVICENAME </code>
* Debian: <code>*FIXME*</code>
* Gentoo: <code>/sbin/rc-update del SERVICENAME</code>

=== Other ===
There might be other adjustments needed. Please add those here if you have more info.

== Starting a new VE ==

Try to start your new VE:

vzctl start 123

Now check that everything works fine. If not, see [[#Troubleshooting]] below.

== Troubleshooting ==

=== Can't enter VE ===

If you can not enter your VE (using <code>vzctl enter</code>), you should be able to at least execute commands in it.

First, see the [[#/dev TTY devices]] section above.

Next, check if devpts is mounted:
vzctl exec 123 mount | grep pts

If it is not mounted, mount it:
vzctl exec 123 mount -t devpts none /dev/pts

Then, add the appropriate mount command to VE's startup scripts. On some distros, you need to have the appropriate line in VE's /etc/fstab.

=== Other problems ===
If anything goes wrong, try to find out why and fix. If you have enough Linux experience, it can be handled. Also check out IRC and please report back on this page.

== Success Stories ==
- Debian 3.1 Sarge with MySQL, apache2, PowerDNS
--[[User:Stoffell|stoffell]] 08:41, 8 February 2007 (EST)

- Red Hat 7.2 with MySQL 3.23, apache, Chilisoft --[[User:Stoffell|stoffell]] 13:26, 9 February 2007 (EST)

- Gentoo with Courier, Postfix, MySQL, Apache2
--[[User:bfrackie|bfrackie]] 19:00, 18 March 2007 (EST)

- AltLinux Master with qmail, MySQL, Apache, etc - to Debian/testing with OpenVZ --[[User:alexkuklin|alexkuklin]]

[[Category:HOWTO]]

Physical to container

2007-03-23T12:16:40Z

Alexkuklin: /* Success Stories */

A rough description of how to migrate existing physical server into a [[VE]].

== Prepare a new “empty” VE ==
For OpenVZ this would mean the following (assume you chose VE ID of 123):

mkdir /vz/root/123 /vz/private/123
cat /etc/vz/conf/ve-vps.basic.conf-sample > /etc/vz/conf/123.conf

== Preparing to migrate ==

Stop most services on a machine to be migrated. “Most” means services such as web server, databases and the like — so you will not loose your data. Just leave the bare minimum (including ssh daemon).

== Copying the data ==

Copy all your data from the machine to an OpenVZ box. Say you'll be using VE with ID of 123, then all the data should be placed to <code>/vz/private/123/</code> directory (so there will be directories such as <code>/vz/private/123/bin</code>, <code>etc</code>, <code>var</code> and so on). This could be done in several ways:

=== rsync ===
rsync example (run from the new HN):
rsync -arvpz --numeric-ids --exclude dev --exclude proc --exclude tmp -e "ssh -l root@a.b.c.d" root@a.b.c.d:/ /vz/private/123/

'''Advantage:''' Your system doesn't really go down.

=== Live CD ===
Another way to do is using a live cd, booting up and use tar to dump the complete disk in a tar you save over the network or on a USB device.

=== Tar ===
Another approach is using tar and excluding some dirs, you could do it like this:

Create a file /tmp/excludes.excl with these contents:
.bash_history
/dev/*
/mnt/*
/tmp/*
/proc/*
/sys/*
/usr/src/*

Then create the tar. But remember, when the system is 'not' using udev, you have to look into /proc/ after creating your VE because some devices might not exist. (/dev/ptmx or others)

# tar cjpf /tmp/mysystem.tar.bz2 / -X /tmp/excludes.excl

Naturally, you can only do this when the critical services (MySQL, apache, ..) are stopped and your /tmp filesystem is big enough to contain your tar.

'''Advantage:''' You don't need to boot from a livecd, so your system doesn't really go down.

== Setting VE parameters ==

=== OSTEMPLATE ===
You have to add <code>OSTEMPLATE=xxx</code> line to <code>/etc/vz/conf/123.conf</code> file, where <code>xxx</code> would be distribution name (like <code>debian-3.0</code>) for vzctl to be able to make changes specific for this distribution.

=== IP address(es) ===
Also, you have to supply an IP for a new VE:

vzctl set 123 --ipadd x.x.x.x --save

== Making adjustments ==
Since VE is a bit different than a real physical server, you have to edit some files inside your new VE.

=== /etc/inittab ===
A VE does not have real ttys, so you have to disable getty in <code>/etc/inittab</code> (i. e. <code>/vz/private/123/etc/inittab</code>).

sed -i -e '/getty/d' /vz/private/123/etc/inittab

=== /etc/mtab ===
Link <code>/etc/mtab</code> to <code>/proc/mounts</code>:

rm -f /vz/private/123/etc/mtab
ln -s /proc/mounts /vz/private/123/etc/mtab

=== /etc/fstab ===
Since you do not have any real disk partitions in a VE, /etc/fstab (or most part of it) is no longer needed. Empty it (excluding the line for /dev/pts):

cp /vz/private/123/etc/fstab /vz/private/123/etc/fstab.old
grep devpts /vz/private/123/etc/fstab.old > /vz/private/123/etc/fstab

You can also mount a devpts in a running (but not fully functional) VE:
vzctl exec 123 mount -t devpts none /dev/pts

=== /dev TTY devices ===
In order for vzctl enter to work, a VE need to have some entries in /dev. This can either be /dev/ttyp* and /dev/ptyp*, or /dev/ptmx and mounted /dev/pts.

==== /dev/ptmx ====
Check that /dev/ptmx exists. If it does not, create with:
mknod /vz/private/123/dev/ptmx c 5 2

==== /dev/pts/ ====
Check that /dev/pts exists. It's a directory, if it does not exist, create with:
mkdir /vz/private/123/dev/pts

==== /dev/ttyp* and /dev/ptyp* ====
Check that /dev/ttyp* and /dev/ptyp* files are there. If not, you have to create those, either by using /sbin/MAKEDEV, or by copying them from the host system.

To copy:
cp -a /dev/ttyp* /dev/ptyp* /vz/private/123/dev/

To recreate with MAKEDEV, either
/sbin/MAKEDEV -d /vz/private/123/dev ttyp ptyp
or
cd /vz/private/123/dev && /sbin/MAKEDEV ttyp

=== Other devices ===

==== /dev/urandom ====
Check that /dev/urandom exists. If it does not, create with:
mknod /vz/private/123/dev/urandom c 1 9

=== /etc/init.d services ===

Some system services can (or in some cases should) be disabled. A few good candidates are:

* acpid, amd (not needed)
* checkfs, checkroot (no filesystem checking is required in VE)
* clock (no clock setting is required/allowed in VE)
* consolefont (VE does not have a console)
* hdparm (VE does not have real hard drives)
* klogd (unless you use iptables to LOG some packets)
* keymaps (VE does not have a real keyboard)
* kudzu (VE does not have real hardware)
* lm_sensors (VE does not have access to hardware sensors)
* microcodectl (VE can not update CPU microcode)
* netplugd (VE does not have real Ethernet device)

To see which services are enabled:
* RedHat/Fedora/SUSE: <code>/sbin/chkconfig --list</code>
* Debian: <code>*FIXME*</code>
* Gentoo: <code>/sbin/rc-update show</code>

To disable the service:
* RedHat/Fedora/SUSE: <code>/sbin/chkconfig --del SERVICENAME </code>
* Debian: <code>*FIXME*</code>
* Gentoo: <code>/sbin/rc-update del SERVICENAME</code>

=== Other ===
There might be other adjustments needed. Please add those here if you have more info.

== Starting a new VE ==

Try to start your new VE:

vzctl start 123

Now check that everything works fine. If not, see [[#Troubleshooting]] below.

== Troubleshooting ==

=== Can't enter VE ===

If you can not enter your VE (using <code>vzctl enter</code>), you should be able to at least execute commands in it.

First, see the [[#/dev TTY devices]] section above.

Next, check if devpts is mounted:
vzctl exec 123 mount | grep pts

If it is not mounted, mount it:
vzctl exec 123 mount -t devpts none /dev/pts

Then, add the appropriate mount command to VE's startup scripts. On some distros, you need to have the appropriate line in VE's /etc/fstab.

=== Other problems ===
If anything goes wrong, try to find out why and fix. If you have enough Linux experience, it can be handled. Also check out IRC and please report back on this page.

== Success Stories ==
- Debian 3.1 Sarge with MySQL, apache2, PowerDNS
--[[User:Stoffell|stoffell]] 08:41, 8 February 2007 (EST)

- Red Hat 7.2 with MySQL 3.23, apache, Chilisoft --[[User:Stoffell|stoffell]] 13:26, 9 February 2007 (EST)

- Gentoo with Courier, Postfix, MySQL, Apache2
--[[User:bfrackie|bfrackie]] 19:00, 18 March 2007 (EST)

- AltLinux Master with qmail, MySQL, Apache, etc - to Debian/testing with OpenVZ --[[User:alexkuklin|alexkuklin]]

[[Category:HOWTO]]