On Thu, Oct 16, 2008 at 7:22 AM, Roberto Scattini <roberto.scattini@xxxxxxxxx> wrote: > hi everybody: > > in a couple of days i will reinstall an offline database server. It's > a old HP Proliant DL580 G3 with three disks (147 GB each). Currently > it has a debian Sarge in a RAID5 hardware array ( with HP Smart Array > 6i, [RAID bus controller: Compaq Computer Corporation Smart Array 64xx > (rev 01)] ). Does that controller have battery backed cache? > i googled a while and get to this page: > http://www.powerpostgresql.com/PerfList , so my first question is, > this document and the tips given hasn't been deprecated by now, right? It's a little old but most of it holds true. > then: > -is raid5 the worst election in this scenario (three disks)? Yes > -which is the best (and with that i mean secure in first place and > with more perfomance in second) possible configuration achievable with > this three disks? either 2 disk mirror w hot spare or 3 disk mirror if the controller supports it. > -should i ask my boss to buy another disk? (it will be difficult, but > if i can demonstrate It worth it...) Yes you should. > i think i will "Separate the Transaction Log from the Database" with > two RAID1 arrays (if they buy the new disk). is this a good way to go? > it would be too bad if i put the logs in a disk without RAID? (only if > i dont get the new disk...) If the controller has battery backed cache, then go with a single RAID 1+0 unless it's really write heavy raid 1+0 will probably be a better choice. Do not use a single disk w no raid. > our application (running on separate webserver) is of the type "OLTP", > the server will be entirely dedicated to postgresql. i will configure > a warm-standby server, so the WAL files will be forwarded to another > server. You should benchmark with two RAID 1s and a single RAID1+0. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
