| Strange performance issue [message #16078] |
Mon, 20 August 2007 20:40  |
vaserv
Messages: 5
Registered: August 2007
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Junior Member |
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I've got a strange performance issue on a host machine that has a number of VPS on it but I wouldn't call overloaded and it seems to be a CPU limit issue but I can't see what
On the host
[root@vz26uk ~]# time perl -e 'sqrt(100) for (0..1000000)'
real 0m0.044s
user 0m0.041s
sys 0m0.003s
Inside the VE
[root@vz26uk ~]# vzctl exec 881980 "time perl -e 'sqrt(100) for (0..1000000)'"
real 0m3.897s
user 0m3.881s
sys 0m0.015s
[root@vz26uk ~]# uname -a
Linux vz26uk.vaserv.com 2.6.9-023stab044.4-smp #1 SMP Mon May 28 23:15:47 MSD 2007 x86_64 x86_64 x86_64 GNU/Linux
[root@vz26uk ~]# uptime
16:32:49 up 5 days, 9:41, 1 user, load average: 1.37, 0.88, 0.67
CPU is Core2Quad with all 4 CPU's detected
[root@vz26uk ~]# free
total used free shared buffers cached
Mem: 6267700 6205080 62620 0 37960 1288820
-/+ buffers/cache: 4878300 1389400
Swap: 2096472 764 2095708
Slighty editted conf file
[root@vz26uk ~]# cat /etc/sysconfig/vz-scripts/881980.conf
ONBOOT="yes"
# UBC parameters (in form of barrier:limit)
# Primary parameters
AVNUMPROC="40:40"
NUMPROC="999999:999999"
NUMTCPSOCK="7999992:7999992"
NUMOTHERSOCK="7999992:7999992"
VMGUARPAGES="131072:2147483647"
# Secondary parameters
KMEMSIZE="2147483646:2147483646"
TCPSNDBUF="107374592:289400832"
TCPRCVBUF="107374592:289400832"
OTHERSOCKBUF="107374592:289400832"
DGRAMRCVBUF="107374592:289400832"
OOMGUARPAGES="131072:2147483647"
# Auxiliary parameters
LOCKEDPAGES="999999:999999"
SHMPAGES="131072:131072"
PRIVVMPAGES="262144:262144"
NUMFILE="23999976:23999976"
NUMFLOCK="999999:999999"
NUMPTY="500000:500000"
NUMSIGINFO="999999:999999"
DCACHESIZE="2147483646:2147483646"
PHYSPAGES="0:2147483647"
NUMIPTENT="999999:999999"
# Disk quota parameters (in form of softlimit:hardlimit)
DISKSPACE="20480000:20480000"
DISKINODES="10240000:10240000"
QUOTATIME="0"
# CPU fair sheduler parameter
CPUUNITS="1000"
VE_ROOT="/vz/root/$VEID"
VE_PRIVATE="/vz/private/881980"
OSTEMPLATE="cpanel"
ORIGIN_SAMPLE="vps.basic"
QUOTAUGIDLIMIT="1000"
CPULIMIT="400"
MEMINFO="pages:262144"
IPTABLES="iptable_filter iptable_mangle ipt_limit ipt_multiport ipt_tos ipt_TOS ipt_REJECT ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_LOG ipt_length ip_conntrack ip_conntrack_ftp ip_conntrack_irc ipt_conntrack ipt_state ipt_helper iptable_nat ip_nat_ftp ip_nat_irc ipt_REDIRECT"
Any ideas what is going on?
Thanks
Rus
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| Re: Strange performance issue [message #16082 is a reply to message #16078] |
Mon, 20 August 2007 21:31  |
locutius
Messages: 125
Registered: August 2007
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Senior Member |
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these values appear very low for your hardware
CPULIMIT="400"
CPUUNITS="1000"
(am i correct the limit should not be smaller than the assigned units for an individual VPS?)
vzcpucheck will give you your current HN limit and you will see immediately you need a sane view on your HN capability. run vzsplit on your HN and split 16 ways then again split 32 ways. compare the output and look at the CPULIMIT values
also from you config it is interesting for you to look at the limits values for:
VMGUARPAGES
OOMGUARPAGES
PRIVVMPAGES
SHMPAGES
EDIT: OFF TOPIC:
i would also consider rebooting the HN to clear that memory logjam. and your SWAP is way too small, i would prefer it was 6GB min
[Updated on: Mon, 20 August 2007 21:32] Report message to a moderator |
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| Re: Strange performance issue [message #16095 is a reply to message #16082] |
Tue, 21 August 2007 05:37 |
devonblzx
Messages: 127
Registered: December 2006
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Senior Member |
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| locutius wrote on Mon, 20 August 2007 17:31 |
these values appear very low for your hardware
CPULIMIT="400"
CPUUNITS="1000"
(am i correct the limit should not be smaller than the assigned units for an individual VPS?)
vzcpucheck will give you your current HN limit and you will see immediately you need a sane view on your HN capability. run vzsplit on your HN and split 16 ways then again split 32 ways. compare the output and look at the CPULIMIT values
also from you config it is interesting for you to look at the limits values for:
VMGUARPAGES
OOMGUARPAGES
PRIVVMPAGES
SHMPAGES
EDIT: OFF TOPIC:
i would also consider rebooting the HN to clear that memory logjam. and your SWAP is way too small, i would prefer it was 6GB min
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CPUUnits is accounted by vzcpucheck, not cpulimit. CPUlimit is 100 for every core/cpu you have. Therefore for a quad-core the maximum is 400. Try raising the cpuunits to more like 100000 instead of 1000, although I'm not sure if that will do anything.
ByteOnSite President
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