Yeah, it seems to be a waste of disk space (spindles as well?). I was unsure how much activity the WAL disks would have compared to the data disks, so I created an array from 10 disks as the application is very write intense (many spindles / high throughput is crucial). I guess that a mirror of two disks is enough from a disk space perspective, but from a throughput perspective it will limit me to ~25Mb/s (roughly calculated). An 0+1 array of 4 disks *could* be enough, but I'm still unsure how WAL activity correlates to "normal data" activity (is it 1:1, 1:2, 1:4, ...?) -----Original Message----- From: pgsql-performance-owner@xxxxxxxxxxxxxx [mailto:pgsql-performance-owner@xxxxxxxxxxxxxx] On Behalf Of Michael Stone Sent: den 17 juli 2006 02:04 To: pgsql-performance@xxxxxxxxxxxxxx Subject: Re: [PERFORM] RAID stripe size question On Mon, Jul 17, 2006 at 12:52:17AM +0200, Mikael Carneholm wrote: >I have finally gotten my hands on the MSA1500 that we ordered some time >ago. It has 28 x 10K 146Gb drives, currently grouped as 10 (for wal) + >18 (for data). There's only one controller (an emulex), but I hope You've got 1.4TB assigned to the WAL, which doesn't normally have more than a couple of gigs? Mike Stone ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
