On Thu, Feb 4, 2010 at 12:11 AM, Andy Colson <a...@squeakycode.net> wrote:
> On 2/3/2010 9:10 AM, Amitabh Kant wrote: > >> Hello >> >> I have a server dedicated for Postgres with the following specs: >> >> RAM 16GB, 146GB SAS (15K) x 4 - RAID 10 with BBU, Dual Xeon E5345 @ >> 2.33GHz >> OS: FreeBSD 8.0 >> >> It runs multiple (approx 10) databases ranging from 500MB to over 24 GB >> in size. All of them are of the same structure, and almost all of them >> have very heavy read and writes. >> >> >> With regards >> >> Amitabh Kant >> > > What problems are you having? Is it slow? Is there something you are > trying to fix, or is this just the first tune up? > This is the first tune up. The system has worked pretty fine till now, but it does lag once in a while, and I would like to optimize it before it becomes a bigger issue. > > > memory allocations. The last time I tried, Postgres refused to start and > > I had to fall back to the default settings. > > Its probably upset about the amount of shared mem. There is probably a way > in bsd to set the max amount of shared memory available. A Quick google > turned up: > > kern.ipc.shmmax > > Dunno if thats right. When you try to start PG, if it cannot allocate > enough shared mem it'll spit out an error message into its log saying how > much it tried to allocate. > > Check: > http://archives.postgresql.org/pgsql-admin/2004-06/msg00155.php > > > > > > > maintenance_work_mem = 960MB # pg_generate_conf wizard 2010-02-03 > > checkpoint_completion_target = 0.9 # pg_generate_conf wizard 2010-02-03 > > effective_cache_size = 11GB # pg_generate_conf wizard 2010-02-03 > > work_mem = 160MB # pg_generate_conf wizard 2010-02-03 > > wal_buffers = 8MB # pg_generate_conf wizard 2010-02-03 > > checkpoint_segments = 16 # pg_generate_conf wizard 2010-02-03 > > shared_buffers = 3840MB # pg_generate_conf wizard 2010-02-03 > > max_connections = 100 # pg_generate_conf wizard 2010-02-03 > > Some of these seem like too much. I'd recommend starting with one or two > and see how it runs. Then increase if you're still slow. > > Start with effective_cache_size, shared_buffers and checkpoint_segments. > > Wait until very last to play with work_mem and maintenance_work_mem. > > > -Andy > I would keep that in mind. Thanks Andy With regards Amitabh
