2011/4/22 Tory M Blue <tmblue@xxxxxxxxx>: > On Fri, Apr 22, 2011 at 4:03 AM, Cédric Villemain > <cedric.villemain.debian@xxxxxxxxx> wrote: >> 2011/4/21 Tory M Blue <tmblue@xxxxxxxxx>: >>> On Thu, Apr 21, 2011 at 7:27 AM, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: >>>> On Thu, Apr 21, 2011 at 3:28 AM, Tory M Blue <tmblue@xxxxxxxxx> 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 postgresql.conf >>>> memory settings? >>>> >>>> merlin >>>> >>> >>> 32bit >>> 32gb >>> PAE kernel >>> >>> # - Checkpoints - >>> checkpoint_segments = 100 >>> max_connections = 300 >>> shared_buffers = 2500MB # min 128kB or max_connections*16kB >>> max_prepared_transactions = 0 >>> work_mem = 100MB >>> maintenance_work_mem = 128MB >>> fsync = on >>> >> >> I didn't understand what value you set for vm.overcommit parameters. >> Can you give it and the values in /proc/meminfo, the interesting one >> are "Commit*" ? >> >> If you have strict rules(overcommit=2), then your current kernel >> config may need some love : the commit_limit is probably too low >> because you have a small swap partition. One way is to change : >> vm.overcommit_ratio. >> By default it should be something like 21GB (0.5*32+5) of >> commit_limit, and you probably want 32GB :) >> >> Maybe you have some minor changes in your install or application usage >> and you just hit the limit. > > Thanks Cedric > > the sysctl vm's are > > # 04/17/2011 to keep overcommit memory in check > vm.overcommit_memory = 2 > vm.overcommit_ratio = 0 > > CommitLimit: 4128760 kB > Committed_AS: 2380408 kB 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 60% should still be safe (60% of 32GB + 5GB) > > > Ya I do think my swap space is biting us, (but again just starting to > grasp that my swap space which has not grown with the continued > addition of memory). I am just not starting to learn that the swap > does need to be properly sized whether it's being used or not. I > figured it would use the swap and it would run out, but sounds like > the system takes the size into consideration and just decides not to > use it. > > I appreciate the totally no postgres responses with this. > > Thanks > Tory > -- Cédric Villemain 2ndQuadrant http://2ndQuadrant.fr/ ; PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
