Performance tuning - Revision history

Sergey Bronnikov: Marked this version for translation

2015-12-26T08:42:08Z

Marked this version for translation

Sergey Bronnikov: add 'translate' tags

2015-12-25T22:49:14Z

add 'translate' tags

Curx: a typo repaired

2009-08-24T15:32:07Z

a typo repaired

Kir: OpenVZ performance tuning moved to Performance tuning: "OpenVZ" was redundant here

2008-09-09T19:29:35Z

OpenVZ performance tuning moved to Performance tuning: "OpenVZ" was redundant here

Kir: double empty lines slashed; no level1 headings; categorized

2008-09-09T19:29:04Z

double empty lines slashed; no level1 headings; categorized

Fayette at 14:49, 4 September 2008

2008-09-04T14:49:01Z

Kir: container's -> containers

2008-03-11T11:06:16Z

container's -> containers

Botinki Kira: Robot: Automated text replacement (-VE +container)

2008-03-11T11:05:37Z

Robot: Automated text replacement (-VE +container)

Kir: /* Virtual Environment tuning / → / Container tuning */

2008-03-11T10:39:04Z

‎Virtual Environment tuning: → ‎Container tuning

Botinki Kira: Robot: Automated text replacement (-VEs +containers)

2008-03-11T09:48:07Z

Robot: Automated text replacement (-VEs +containers)

@@ Line 1: / Line 1: @@
 <translate>
 This page describes how to improve the performance of an OpenVZ system.
-== HW node environment tuning ==
+== HW node environment tuning == <!--T:2-->
-=== Disable unnecessary services ===
+=== Disable unnecessary services === <!--T:3-->
 Disable all default services that you do not need to use and then reboot your host.
 For example, the <code>audit</code> daemon can significantly decrease performance of linux kernel system calls (up to ~<font color=red>20%</font>) even if you do not use any audit rules, or even if you just stopped this service without host reboot!
 To setup default services, use <code>chkconfig</code> or <code>ntsysv</code> in RedHat, or <code>rc-update</code> in Gentoo, <code>update-rc.d</code> on Debian
-=== Shell scripts performance improvement ===
+=== Shell scripts performance improvement === <!--T:7-->
 To improve performance of small shell scripts, which spends a lot of time starting the shell binary itself (like the shell scripts test from the [http://www.tux.org/pub/tux/niemi/unixbench/ unixbench] package), you can set your <code>LANG</code> environment variable to <code>"C"</code>.
 To see current settings, type
-   # locale
+   <!--T:10-->
 If you want to change it only for the current shell session, do:
-  # export LANG=C
+  <!--T:12-->
 If you want to change the default value, modify the <code>/etc/sysconfig/i18n</code> file.
 If your default <code>LANG</code> environment variable was set to something like <code>en_US.UTF-8</code>, you can reduce shell (bash) startup time up to ~<font color=red>15%</font> with <code>LANG=C</code>.
-== Container tuning ==
+== Container tuning == <!--T:15-->
-=== CPU distribution inside container on SMP hosts ===
+=== CPU distribution inside container on SMP hosts === <!--T:16-->
 If the total number of containers in your host is more than CPUs number, and there are many '''threads''' running inside each container it is better to give just a single VCPU to each container.
 In this case thread memory locality will significantly reduce overhead on SMP memory coherence and overall performance can be increased up to ~<font color=red>50-100%</font>!
 To set the number of CPUs available inside a container, use:
-  # vzctl set $CTID --cpus N
+  <!--T:19-->
-=== Network checksumming ===
+=== Network checksumming === <!--T:20-->
 RHEL 5 based kernel supports IP checksum offload.
 If network ethernet cards in your host support IP checksum offload then you can switch this feature on also for the virtual network devices (venet, veth).
 To check current offload setting for the hardware ethernet card (eth0, for instance) type
-   # ethtool -k eth0
+   <!--T:23-->
 Make sure that tx/rx features are switched on.
 To see current offload settings for the venet0 device, type
-   # ethtool -k venet0
+   <!--T:25-->
 To set offload settings on for the venet0 device, type
-   # ethtool -K venet0 tx on sg on
+   <!--T:27-->
 Note, that 'tx on/off' enables/disables both tx and rx checksumming features for the all venet devices for all containers and HN.
 The same applies to the veth device except that 'tx on/off' enables/disables tx and rx checksumming features for only given virtual ethernet device in HN and corresponding container.
-=== Shell scripts performance improvement ===
+=== Shell scripts performance improvement === <!--T:30-->
 Please note, that on container creation the default <code>LANG</code> value will be the same as in the HW node. So you can tune it in node (see [[#Shell scripts performance improvement]] above), or set it in container the same way.
 The second important thing is the locale cache. On <code>rpm</code> based distributions, usually it is created by the <code>glibc-common-XXX.rpm</code> post install script and it can be up to 50 MBytes on some distributions. So on some container templates it can be missed to save disk space. But you can always create it inside container later by the following command (you must be the root user):
-  # build-locale-archive
+  <!--T:33-->
 And again, in some cases shell (bash) startup time can be reduced up to ~<font color=red>15%</font>.
 </translate>

@@ Line 1: / Line 1: @@
 This page describes how to improve the performance of an OpenVZ system.
@@ Line 70: / Line 71: @@
 And again, in some cases shell (bash) startup time can be reduced up to ~<font color=red>15%</font>.
 [[Category: HOWTO]]
 [[Category: Troubleshooting]]

@@ Line 9: / Line 9: @@
 For example, the <code>audit</code> daemon can significantly decrease performance of linux kernel system calls (up to ~<font color=red>20%</font>) even if you do not use any audit rules, or even if you just stopped this service without host reboot!
-To setup default services, use <code>chkconfig</code> or <code>ntsysv</code> in RedHat, or <code>rc-update</code> in Gentoo, <code>update-rc.dv</code> on Debian
+To setup default services, use <code>chkconfig</code> or <code>ntsysv</code> in RedHat, or <code>rc-update</code> in Gentoo, <code>update-rc.d</code> on Debian
 === Shell scripts performance improvement ===

@@ Line 1: / Line 1: @@
 This page describes how to improve the performance of an OpenVZ system.
-= HW node environment tuning =
+== HW node environment tuning ==
-== Disable unnecessary services ==
+=== Disable unnecessary services ===
 Disable all default services that you do not need to use and then reboot your host.
 For example, the <code>audit</code> daemon can significantly decrease performance of linux kernel system calls (up to ~<font color=red>20%</font>) even if you do not use any audit rules, or even if you just stopped this service without host reboot!
 To setup default services, use <code>chkconfig</code> or <code>ntsysv</code> in RedHat, or <code>rc-update</code> in Gentoo, <code>update-rc.dv</code> on Debian
-== Shell scripts performance improvement ==
+=== Shell scripts performance improvement ===
 To improve performance of small shell scripts, which spends a lot of time starting the shell binary itself (like the shell scripts test from the [http://www.tux.org/pub/tux/niemi/unixbench/ unixbench] package), you can set your <code>LANG</code> environment variable to <code>"C"</code>.
 To see current settings, type
@@ Line 27: / Line 24: @@
 If you want to change the default value, modify the <code>/etc/sysconfig/i18n</code> file.
 If your default <code>LANG</code> environment variable was set to something like <code>en_US.UTF-8</code>, you can reduce shell (bash) startup time up to ~<font color=red>15%</font> with <code>LANG=C</code>.
-= Container tuning =
+== Container tuning ==
-== CPU distribution inside container on SMP hosts ==
+=== CPU distribution inside container on SMP hosts ===
-* If the total number of containers in your host is more than CPUs number, and there are many '''threads''' running inside each container it is better to give just a single VCPU to each container.
+If the total number of containers in your host is more than CPUs number, and there are many '''threads''' running inside each container it is better to give just a single VCPU to each container.
 In this case thread memory locality will significantly reduce overhead on SMP memory coherence and overall performance can be increased up to ~<font color=red>50-100%</font>!
-To set the number of CPUs available inside container use:
+To set the number of CPUs available inside a container, use:
   # vzctl set $CTID --cpus N
-== Network checksumming ==
+=== Network checksumming ===
 RHEL 5 based kernel supports IP checksum offload.
@@ Line 65: / Line 61: @@
 The same applies to the veth device except that 'tx on/off' enables/disables tx and rx checksumming features for only given virtual ethernet device in HN and corresponding container.
-== Shell scripts performance improvement ==
+=== Shell scripts performance improvement ===
 Please note, that on container creation the default <code>LANG</code> value will be the same as in the HW node. So you can tune it in node (see [[#Shell scripts performance improvement]] above), or set it in container the same way.
 The second important thing is the locale cache. On <code>rpm</code> based distributions, usually it is created by the <code>glibc-common-XXX.rpm</code> post install script and it can be up to 50 MBytes on some distributions. So on some container templates it can be missed to save disk space. But you can always create it inside container later by the following command (you must be the root user):
@@ Line 76: / Line 70: @@
 And again, in some cases shell (bash) startup time can be reduced up to ~<font color=red>15%</font>.

← Older revision		Revision as of 14:49, 4 September 2008
Line 1:		Line 1:
−	This page describes how to improve performance of OpenVZ system.	+	This page describes how to improve the performance of an OpenVZ system.

	= HW node environment tuning =		= HW node environment tuning =

← Older revision	Revision as of 19:29, 9 September 2008
(No difference)

@@ Line 31: / Line 31: @@
 If your default <code>LANG</code> environment variable was set to something like <code>en_US.UTF-8</code>, you can reduce shell (bash) startup time up to ~<font color=red>15%</font> with <code>LANG=C</code>.
-= Virtual Environment tuning =
+= Container tuning =
 == CPU distribution inside VE on SMP hosts ==

@@ Line 61: / Line 61: @@
    # ethtool -K venet0 tx on sg on
-Note, that 'tx on/off' enables/disables both tx and rx checksumming features for the all venet devices for all VEs and HN.
+Note, that 'tx on/off' enables/disables both tx and rx checksumming features for the all venet devices for all containers and HN.
 The same applies to the veth device except that 'tx on/off' enables/disables tx and rx checksumming features for only given virtual ethernet device in HN and corresponding VE.