Would love to get some advice on how to change my conf settings / setup to get better I/O performance.
Server Specs:
2x Intel Xeon Quad Core (@2 Ghz - Clovertown,L5335)
4GB RAM
4x Seagate 73GB SAS HDD 10k RPM – in RAID ( stripped and mirrored )
FreeBSD 6.4
Apache 2.2
PostgreSQL 8.3.6
PHP 5.2.9
~1500 databases w/ ~60 tables each
Total I/O (these number are pretty constant throughout the day):
Reads: ~ 100 / sec for about 2.6 Mb/sec
Writes: ~ 400 /sec for about 46.1Mb/sec
Conf settings:
listen_addresses = '*'
max_connections = 600
ssl = on
password_encryption = on
shared_buffers = 1GB
work_mem = 5MB
maintenance_work_mem = 256MB
max_fsm_pages = 2800000
max_fsm_relations = 160000
synchronous_commit = off
checkpoint_segments = 6
checkpoint_warning = 30s
effective_cache_size = 1GB
pg_stat_bgwriter:
checkpoints_timed: 16660
checkpoints_req: 1309
buffers_checkpoint: 656346
buffers_clean: 120922
maxwritten_clean: 1
buffers_backend: 167623
buffers_alloc: 472802349
This server also handles web traffic and PHP script processing.
Most of the SQL happening is selects – very little inserts, updates and deletes comparatively.
I have noticed that most/all of the I/O activity is coming from the stats collector and autovacuum processes. Would turning off the stats collector and autovacuum be helpeful / recommended? Could I change my checkpoint_* or bgwriter_* conf values to help?
Let me know if you need more information / stats.
Any help would be much appreciated.
Thanks,
Scott Otis
CIO / Lead Developer
Intand
www.intand.com
