OpenVZ Virtuozzo Containers Wiki - User contributions [en]

Support

2009-07-11T10:58:19Z

Netvoice: Updated information on support.

__NOTOC__
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== OpenVZ ==
You can get support through the [[mailing list]], [[bugzilla:|Bugzilla]]
and [http://forum.openvz.org/index.php?t=thread&frm_id=2 Support forum].
Both developers and members of OpenVZ community can answer
your questions there, although there is no guarantee of any kind. Be
sure to browse/search this wiki, make a search within the mailing list archives and forums
before asking your question.
| bgcolor="#f0fff8" valign="top" width="33%" |
== Supported OpenVZ ==
''Supported OpenVZ is the same as OpenVZ '''{{red|plus}}''':''
* 24×7 email support (withing 6 hours during business hours).
* Three support incidents per month.
* Direct system support via the Internet (SSH) for the resolution of specific issues and system optimization.

Support contracts are available for a decent price per
physical server per year. Bulk discounts are available. Contact sales@openvz.org for further details.

THIS SERVICE MAY NOT EXIST ANYMORE. My attempts to purchase support for OpenVZ from parallels
were refused and my money was returned.
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== Parallels Virtuozzo Containers ==
''Parallels Virtuozzo Containers provides everything Supported OpenVZ does '''{{red|plus}}''':''
* Higher containers per node density.
* Name-based hosting (no need for public IP for each container).
* Installation utility.
* Offline web-based containers management.
* Traffic accounting tools.
* Containers backup tools.
* Physical-to-Container and Container-to-Physical migration tools.
* Monitoring and statistics tools.
* Common client-server XML-based management API.
* Web-based and GUI management tools:
** Parallels Management Console – GUI systems administrator management tool.
** Parallels Infrastructure Manager – Web-based systems administrator management tool.
* Integration with [http://www.parallels.com/plesk/ Parallels Plesk Control Panel].
* Discounts on Parallels Plesk Control Panel licenses.
|}

For more information, visit [http://www.parallels.com/ parallels.com] or contact sales@parallels.com.

== Training ==

Standard training courses are available. The courses are designed to train the participants in the product features, functions, installation, configuration and maintenance. The participants will obtain an in-depth knowledge of the product and the impact the product can have on their business. The participants can select from different levels and types of training, including onsite classes and remote online sessions.

Contact training@openvz.org for further details.

Resource shortage

2009-03-21T10:04:11Z

Netvoice: Additional explanation of cpulimit on multi-core servers.

Sometimes you see strange failures from some programs inside your [[container]]. In some cases it means one of the resources controlled by OpenVZ has hit the limit.

The first thing to do is to check the contents of the /proc/user_beancounters file in your [[container]]. The last column of output is the fail counter. Each time a resource hits the limit, the fail counter is incremented. So, if you see non-zero values in the failcnt column that means something is wrong.

There are two ways to fix the situation: reconfigure (in some cases recompile) the application, or change the resource management settings.

== [[UBC]] parameters ==

Here is an example of current [[UBC]] values obtained from <code>/proc/user_beancounters</code> file in container 123:
<pre>
# cat /proc/user_beancounters
Version: 2.5
uid resource held maxheld barrier limit failcnt
123: kmemsize 836919 1005343 2752512 2936012 0
lockedpages 0 0 32 32 0
privvmpages 4587 7289 49152 53575 0
shmpages 39 39 8192 8192 0
dummy 0 0 0 0 0
numproc 20 26 65 65 0
physpages 2267 2399 0 2147483647 0
vmguarpages 0 0 6144 2147483647 0
oomguarpages 2267 2399 6144 2147483647 0
numtcpsock 3 3 80 80 0
numflock 3 4 100 110 0
numpty 1 1 16 16 0
numsiginfo 0 1 256 256 0
tcpsndbuf 0 0 319488 524288 0
tcprcvbuf 0 0 319488 524288 0
othersockbuf 6684 7888 132096 336896 0
dgramrcvbuf 0 8372 132096 132096 0
numothersock 8 10 80 80 0
dcachesize 87672 92168 1048576 1097728 0
numfile 238 306 2048 2048 0
dummy 0 0 0 0 0
dummy 0 0 0 0 0
dummy 0 0 0 0 0
numiptent 10 16 128 128 0
</pre>

You can see if you hit the limit for some [[UBC]] parameters by analyzing the last column (named <code>failcnt</code>). It shows a number of failures for this counter, i.e. a number of times a parameter hit the limit. Usually what you need to do is to increase the parameter in question. But you need to do it carefully, and here is how.

<ol>
<li>Get the current values for the parameter's barrier and limit. For example, we want to increase kmemsize values. From <code>/proc/user_beancounters</code> we see that <code>kmemsize</code> barrier is 2752512, and its limit is 2936012.
</li>

<li>Increase the values. Say, we want to double <code>kmemsize</code>. This is how it can be done using built-in bash arithmetics:
<pre>
# vzctl set 123 --kmemsize $((2752512*2)):$((2936012*2)) --save
</pre>
By using the <code>--save</code> flag, we indicate we want to apply the new setting to the running container and save it in the configuration file (from which the settings will be taken during next container start).
</li>

<li>Check the new configuration. Issue the following command:
<pre>
# vzcfgvalidate /etc/vz/conf/123.conf
</pre>
If something is wrong, you need to fix it as suggested by the utility.
</li>
</ol>

For more in-depth explanation of different parameters, their meaning and how to set them properly, see [[setting UBC parameters]].

== Disk quota ==
To check if your [[container]] exceeded its disk quota, use the following commands (inside a container):
<pre>
# df
Filesystem 1K-blocks Used Available Use% Mounted on
simfs 1048576 327664 720912 32% /
# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
simfs 200000 18857 181143 10% /
</pre>

The first command shows disk space usage and the second command shows the inodes usage (you can roughly use the inodes count as a number of files/directories on your system).

If one of the commands shows a usage of 100% you have exceeded one of the disk quota limits.

You can increase the limit from the host system ([[CT0]] [[aka]] [[VE0]]) only. This is how:
<ol>
<li>Get the current values for disk quota:
<pre># vzquota stat 123
resource usage softlimit hardlimit grace
1k-blocks 327664 1048576 1153434
inodes 18857 200000 220000
</pre>
</li>

<li>To increase the disk space quota, use vzctl set --diskspace. For example, we want to increase it by a factor of 2:
<pre>
vzctl set 123 --diskspace $(( 1048576*2 )):$(( 1153434*2 )) --save
</pre>
</li>

<li>To increase the disk inodes quota, use <tt>vzctl set --diskinodes</tt>. For example, we want to increase it by a factor of 3:
<pre>
vzctl set 123 --diskinodes $(( 200000*3 )):$(( 220000*3 )) --save
</pre>
</li>
</ol>

{{Note|shell does not support floating-point arithmetic, i.e. you can not use expressions like <code>$(( 220000*1.5 ))</code>. To use floating point, try <code>bc</code> instead, something like this: <code><nowiki>$(echo 220000*1.5 | bc)</nowiki></code>.}}

== CPU ==

There are two parameters controlling fair CPU scheduler in OpenVZ: cpuunits and cpulimit.

=== cpuunits ===
Cpuunits are set via
<pre>
vzctl set 101 --cpuunits 1000 --save
</pre>
For example. If you set a cpuunit for one container to a value and set a cpuunit on another container to a different value, the time allotted to each of the containers will be the ratio of the two units. Let's use a real example.

We did the following:
<pre>
vzctl set 101 --cpuunits 1000 --save
vzctl set 102 --cpuunits 2000 --save
vzctl set 103 --cpuunits 3000 --save
</pre>

If we started a CPU intensive application on each CT, then 103 would be given 3 times as much cpu time as 101 and 102 would get twice as much as 101, but some fraction of what 103 got. Here's how to determine what the real ratios are.

Add the three units, 1000+2000+3000 = 6000

101 gets 1000/6000 or 1/6th of the time. (16%)
102 gets 2000/6000 or 1/3rd of the time. (34%)
103 gets 3000/6000 or 1/2 of the time. (50%)

=== cpulimit ===

The cpulimit parameter sets the absolute maximum limit for a container to a percent value. For instance:
<pre>
vzctl set 101 --cpulimit 25 --save
</pre>
says that container 101 cannot ever have more than 25 percent of a CPU even if the CPU is idle for the other 75% of the time. The limit is calculated as a percentage of a single CPU, not as a percentage of the server's CPU resources as a whole. In other words, if you have more than one CPU, you can set a cpulimit > 100. In a quad-core server, setting cpulimit to 100 permits a container to consume one entire core (and not 100% of the server).

{{Warning|cpulimit is not yet implemented in kernels > 2.6.18 (i.e. development ones). Use stable kernel if you want this feature.}}

{{Stub}}

[[Category: Troubleshooting]]
[[Category: HOWTO]]
[[Category: UBC]]
[[Category: Resource management]]
[[Category: Disk quota]]

User:Netvoice

2008-03-09T02:19:04Z

Netvoice: New page: [http://www.netvoice.ca/ netVOICE communications] is a small ITSP that uses OpenVZ to provide Virtual Private [http://www.asterisk.org/ Asterisk] Servers [http://www.vpas.ca/ (VPAS)]. Our...

[http://www.netvoice.ca/ netVOICE communications] is a small ITSP that uses
OpenVZ to provide Virtual Private [http://www.asterisk.org/ Asterisk] Servers
[http://www.vpas.ca/ (VPAS)].

Our contributions to this Wiki are based on the experience of running a number of
OpenVZ servers (running on dual- and quad-core Xeon processors).

OpenVZ rocks! Thanks all for an incredible piece of software technology.

UBC Monitoring

2008-03-09T02:14:09Z

Netvoice: finally figured out how to make external links work (mediawiki documentation is hard to search)

Monitoring /proc/user_beancounters to see if any VEs are hitting limits is an important part of
managing an OpenVZ installation. VEs that are hitting key limits can have applications malfunction in strange
ways that can only be diagnosed by realising that it is a UBC configuration issue.

This script, when run periodically (using cron) will detect changes in the failcnt field of /proc/user_beancounters

[http://img.cs.montana.edu/linux/openvz/failcnt.py failcnt.py]

[[Category: Troubleshooting]]

UBC Monitoring

2008-03-09T02:11:37Z

Netvoice:

Monitoring /proc/user_beancounters to see if any VEs are hitting limits is an important part of
managing an OpenVZ installation. VEs that are hitting key limits can have applications malfunction in strange
ways that can only be diagnosed by realising that it is a UBC configuration issue.

This script, when run periodically (using cron) will detect changes in the failcnt field of /proc/user_beancounters

[[failcnt.py http://img.cs.montana.edu/linux/openvz/failcnt.py]]

[[Category: Troubleshooting]]

UBC Monitoring

2008-03-09T02:10:50Z

Netvoice: New page: Monitoring the /proc/user_beancounters to see if any VEs are hitting limits is an important part of managing an OpenVZ installation. VEs that are hitting key limits can have applications m...

Monitoring the /proc/user_beancounters to see if any VEs are hitting limits is an important part of
managing an OpenVZ installation. VEs that are hitting key limits can have applications malfunction in strange
ways that can only be diagnosed by realising that it is a UBC configuration issue.

This script, when run periodically (using cron) will detect changes in the failcnt field of /proc/user_beancounters

[[http://img.cs.montana.edu/linux/openvz/failcnt.py]]

[[Category: Troubleshooting]]

Partners

2007-10-27T05:11:15Z

Netvoice: added netVOICE communications

Here are some companies that are working together with OpenVZ project in one or another way. Feel free to add your company profile here (in alpha order).

== Computer Tyme ==
[http://ctyme.com Computer Tyme] is using OpenVZ for their spam filtering service [http://junkemailfilter.com Junk Email Filter dot com]. They are active proponents of OpenVZ; Marc Perkel worked at the OpenVZ booth during LinuxWorld Expo 2007.

== netVOICE communications ==
[http://www.netvoice.ca/ netVOICE communications] is an Internet Telephony Service Provider (ITSP) that uses OpenVZ as the basis for their [http://www.vpas.ca/ Virtual Private Asterisk Server (VPAS)] offering. They also offer consulting on running Asterisk (the leading Open Source telephony platform) on OpenVZ. netVOICE is a Digium Approved Reseller and has a Digium Certified Asterisk Professional [http://www.digium.com/en/training/certifications/ (dCAP)] on staff.

== Proxmox ==

[http://proxmox.com Proxmox] is [http://www.proxmox.com/cms_proxmox/en/virtualization/openvz/ using OpenVZ] for their spam filtering appliance (see [[Proxmox Mail Gateway in VE]]). Proxmox is also the author of [http://www.proxmox.com/cms_proxmox/en/virtualization/openvz/vzdump/ vzdump] utility.

== See also ==

* [[Control panels]]