Steve, > I help manage an animal hospital of 100-employees Linux servers. I am > new to database setup and tuning, I was hoping I could get some > direction on a setting up drive array we're considering moving our > database to.
Check what I have to say at http://www.powerpostgresql.com/PerfList > They're currently on a two-disk Adaptec RAID1 with Postgresql 7.4.2. And you've not upgraded to 7.4.6 because .... ? > The drive array is a 7-disk fibre channel on a Qlogic 2100 controller. I > am currently testing RAID5 (sw). In general, RAID 5 is not so great for databases. See the article for more. > The main reason of moving to a drive array is the high level of context > switches we get during the day (>30K for 20 mins per hour). The OS and > database exist on the same disk but seperate parition (which probably > makes little difference) Unfortunately, the context switches are probably due to a known issue in PostgreSQL, and changing the drive array won't help this issue (it may help other issues though). Search the archives of this list, and pgsql-hackers, for "Context Switch Bug". For the CS bug, the only workaround right now is to avoid the query structures that trigger it. > Server Info: > Centos 3.3 (RHEL 3.x equivelent) > 4GB RAM > Adaptec 2100S RAID > Qlogic QLA2100 Fibre CPU? -- Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
