We're upgrading to a medium-sized server, a Dell PowerEdge 2950, dual-quad CPU's and 8 GB memory. This box can hold at most 8 disks (10K SCSI 2.5" 146 GB drives) and has Dell's Perc 6/i RAID controller.
I'm thinking of this:
6 disks RAID 1+0 Postgres data
1 disk WAL
1 disk Linux
I've often seen RAID 1 recommended for the WAL. Is that strictly for reliability, or is there a performance advantage to RAID 1 for the WAL?
It seems to me separating the OS and WAL on two disks is better than making a single RAID 1 and sharing it, from a performance point of view.
Thanks,
Craig