How to increase SHMMAX for virtual OS? [message #8330] |
Thu, 16 November 2006 08:17 ![Go to next message Go to next message](/theme/ovz3/images/down.png) |
Siaco
Messages: 2 Registered: November 2006
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Junior Member |
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Hi.
I'm trying to run PostgreSQL on virtual system and I need to increase SHMMAX to be able to assign a higher than default value for shared_buffers parameter (essential for performance). I've tried to increase 'shmpages' parameter, but I suppose that I did not calculate peges to bytes properly. Or, maybe, do I have to change other parameters too?
Error message during starting postgreSQL with too high shared_buffers value is typical for too low shmmax (in real OS). PostgreSQL cannot start even at shared_buffers set to 4000 (in 8KB pages -> 32 MB). The requested segment size is 36184064.
And here are my kernel settings. Most of them calculated by vzsplit, shmpages changed manually.
Version: 2.5
uid resource held maxheld barrier limit failcnt
110: kmemsize 2074026 4280348 69857006 76842706 0
lockedpages 0 0 3410 3410 0
privvmpages 2107 22409 153494 168843 0
shmpages 0 6794 46184064 46184064 0
dummy 0 0 0 0 0
numproc 19 44 2666 2666 0
physpages 1184 15973 0 9223372036854775807 0
vmguarpages 0 0 153494 9223372036854775807 0
oomguarpages 1184 15973 153494 9223372036854775807 0
numtcpsock 5 6 2666 2666 0
numflock 3 4 1000 1100 0
numpty 0 1 266 266 0
numsiginfo 0 3 1024 1024 0
tcpsndbuf 86880 0 12365733 23285669 0
tcprcvbuf 81920 0 12365733 23285669 0
othersockbuf 35464 49936 6182866 17102802 0
dgramrcvbuf 0 9680 6182866 6182866 0
numothersock 21 32 2666 2666 0
dcachesize 0 0 15246664 15704064 0
numfile 1134 2098 27264 27264 0
dummy 0 0 0 0 0
dummy 0 0 0 0 0
dummy 0 0 0 0 0
numiptent 10 10 200 200 0
Is there a more advanced howto about setting kernel parameters?
R.
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Re: How to increase SHMMAX for virtual OS? (postgresql) [message #8347 is a reply to message #8335] |
Thu, 16 November 2006 15:13 ![Go to previous message Go to previous message](/theme/ovz3/images/up.png) |
Siaco
Messages: 2 Registered: November 2006
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Junior Member |
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Thanks, but...
Either it doesn't work, or problem is located elsewhere.
It's now clear, that I have 1 page=4KB. Thus I'm setting shared_buffers in postgresql to 4000 (8KB pages) and SHMPAGES to 12000. It is clear, that 32 MB of shared mem in postgresql is less than 48 MB for whole virtual env, but PostgreSQL still cannot start.
SHMPAGES does'nt appear in 'consistency check' table. vzcfgvalidate reports success.
Do you have any other ideas?
R.
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