Re: [PERFORM] OT (slightly) testing for data loss on an SSD drive due to power failure

2011-04-22 Thread Greg Smith
On 04/22/2011 10:04 AM, John Rouillard wrote: We have a couple of ssd's 2 x 160GB Intel X25-M MLC SATA acting as the zil (write journal) and are trying to see if it is safe to use for a power fail situation. Well, the quick answer is "no". I've lost several weekends of my life to recoveri

Re: [PERFORM] oom_killer

2011-04-22 Thread Claudio Freire
On Fri, Apr 22, 2011 at 6:45 PM, Cédric Villemain wrote: > Are you sure it is a PAE kernel ? You look limited to 4GB. If my memory/knowledge serves me right, PAE doesn't remove that limit. PAE allows more processes, and they can use more memory together, but one process alone has to live within a

Re: [PERFORM] postgresql random io test with 2 SSD Kingston V+100 500GB in (software) Raid1

2011-04-22 Thread Marinos Yannikos
Am 19.04.2011 11:15, schrieb Laurent Laborde: Soft RAID1 (md) ext3 We have experimented a bit with Postgres and ext3 (with and without Linux software RAID1) and have found that since somewhere after 2.6.18, it has been prohibitively slow and causing high latencies during buffer flushes. You w

Re: [PERFORM] oom_killer

2011-04-22 Thread Cédric Villemain
2011/4/22 Tory M Blue : > On Fri, Apr 22, 2011 at 9:45 AM, Cédric Villemain > wrote: > >>> CommitLimit:     4128760 kB >>> Committed_AS:    2380408 kB >> >> Are you sure it is a PAE kernel ? You look limited to 4GB. > > Figured that the Commitlimit is actually the size of swap, so on one > server

Re: [PERFORM] oom_killer

2011-04-22 Thread Tory M Blue
On Fri, Apr 22, 2011 at 9:45 AM, Cédric Villemain wrote: >> CommitLimit:     4128760 kB >> Committed_AS:    2380408 kB > > Are you sure it is a PAE kernel ? You look limited to 4GB. Figured that the Commitlimit is actually the size of swap, so on one server it's 4gb and the other it's 5gb. So s

Re: [PERFORM] oom_killer

2011-04-22 Thread Tory M Blue
On Fri, Apr 22, 2011 at 11:15 AM, David Rees wrote: > On Thu, Apr 21, 2011 at 1:28 AM, Tory M Blue wrote: >> this is a Fedora 12 system, 2.6.32.23-170. I've been reading and >> appears this is yet another fedora bug, but so far I have not found >> any concrete evidence on how to fix it. > > If it

Re: [PERFORM] oom_killer

2011-04-22 Thread David Rees
On Thu, Apr 21, 2011 at 1:28 AM, Tory M Blue wrote: > this is a Fedora 12 system, 2.6.32.23-170. I've been reading and > appears this is yet another fedora bug, but so far I have not found > any concrete evidence on how to fix it. If it's a "fedora" bug, it's most likely related to the kernel whe

Re: [PERFORM] oom_killer

2011-04-22 Thread Tory M Blue
On Fri, Apr 22, 2011 at 9:46 AM, Cédric Villemain wrote: > 2011/4/22 Cédric Villemain : >> Are you sure it is a PAE kernel ? You look limited to 4GB. >> >> I don't know atm if overcommit_ratio=0 has a special meaning, else I >> would suggest to update it to something like 40% (the default), but

Re: [PERFORM] oom_killer

2011-04-22 Thread Cédric Villemain
2011/4/22 Cédric Villemain : > 2011/4/22 Tory M Blue : >> On Fri, Apr 22, 2011 at 4:03 AM, Cédric Villemain >> wrote: >>> 2011/4/21 Tory M Blue : On Thu, Apr 21, 2011 at 7:27 AM, Merlin Moncure wrote: > On Thu, Apr 21, 2011 at 3:28 AM, Tory M Blue wrote: >> Fedora 12 >> 32g

Re: [PERFORM] oom_killer

2011-04-22 Thread Cédric Villemain
2011/4/22 Tory M Blue : > On Fri, Apr 22, 2011 at 4:03 AM, Cédric Villemain > wrote: >> 2011/4/21 Tory M Blue : >>> On Thu, Apr 21, 2011 at 7:27 AM, Merlin Moncure wrote: On Thu, Apr 21, 2011 at 3:28 AM, Tory M Blue wrote: >>> > Fedora 12 > 32gig memory, 8 proc > postgres 8.4.4,

Re: [PERFORM] oom_killer

2011-04-22 Thread Tory M Blue
On Fri, Apr 22, 2011 at 9:34 AM, Kevin Grittner wrote: > Tory M Blue wrote: > >> I appreciate the totally no postgres responses with this. > > I didn't understand that.  What do you mean? > > -Kevin I meant that when starting to talk about kernel commit limits/ etc, it's not really postgres cent

Re: [PERFORM] oom_killer

2011-04-22 Thread Kevin Grittner
Tory M Blue wrote: > I appreciate the totally no postgres responses with this. I didn't understand that. What do you mean? -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-pe

Re: [PERFORM] oom_killer

2011-04-22 Thread Tory M Blue
On Fri, Apr 22, 2011 at 4:03 AM, Cédric Villemain wrote: > 2011/4/21 Tory M Blue : >> On Thu, Apr 21, 2011 at 7:27 AM, Merlin Moncure wrote: >>> On Thu, Apr 21, 2011 at 3:28 AM, Tory M Blue wrote: >> Fedora 12 32gig memory, 8 proc postgres 8.4.4, slony 1.20 5 gigs of swap (ne

[PERFORM] OT (slightly) testing for data loss on an SSD drive due to power failure

2011-04-22 Thread John Rouillard
Hi all: I realize this is slightly off topic, but is an issue of concern with the use of ssd's. We are setting up a storage server under solaris using ZFS. We have a couple of ssd's 2 x 160GB Intel X25-M MLC SATA acting as the zil (write journal) and are trying to see if it is safe to use for a p

Re: [PERFORM] oom_killer

2011-04-22 Thread Cédric Villemain
2011/4/21 Tory M Blue : > On Thu, Apr 21, 2011 at 7:27 AM, Merlin Moncure wrote: >> On Thu, Apr 21, 2011 at 3:28 AM, Tory M Blue wrote: > >>> Fedora 12 >>> 32gig memory, 8 proc >>> postgres 8.4.4, slony 1.20 >>> 5 gigs of swap (never hit it!) >> >> curious: using 32/64 bit postgres? what are your

[PERFORM] Checkpoint execution overrun impact?

2011-04-22 Thread drvillo
Hi all I'm trying to track down the causes of an application crash and reviewing PG logs I'm seeing this: 2011-04-22 06:00:16 CEST LOG: checkpoint complete: wrote 140 buffers (3.4%); 0 transaction log file(s) added, 0 removed, 0 recycled; write=27.937 s, sync=1.860 s, total=29.906 s 2011-04-22 0