SLUG Mailing List ArchivesSLUG Mailing List ArchivesOn Thu, May 05, 2005 at 04:15:21PM +1000, Michael Chesterton wrote: > Peter Rundle <prundle@xxxxxxxxxxxxxx> writes: > > > System has hardware raid with six drives. Two 36Gb and four 72Gb. Idea > > is to mirror two 36's as the system disk > > and the other 4 in a raid 5 for data. System will be a bit of a jack of > > Looks fine to me. If 144G was enough for the data, I would use raid > 1+0 (or is that 0+1 or 10). With 4 disks, raid 1+0 is faster at > reading and writing than raid 5 with the same amount of redundancy. Q) isn't raid 1+0 of 4 disk = 144G and raid 5 of 4 disk 216G of space I thought the formula for raid 1 is N/2 and the +0 was that the data was striped across different spindles, were as the formula for raid5 was N-1 (loose 1 drive for parity) > > I'd also look into the optimum file system block size for your raid > setup, from memory you want to match the raid block size with the file > system block size. I would double check that, though, it's covered in > a howto I think. > > I'd put the 4 disks on /var and partition the system disk with / /usr > /home and swap. > > It's well worth your time tuning postgres, there are a number of > articles on how to do it (google tuning postgresql performance), but > without gobs of experience, it's mostly trial and error. I've had > queries that were taking minutes to complete come down to seconds. > > That's my string. > -- > SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ > Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html >
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