Re: How to allocate 8 disks

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On Sat, 01 Mar 2008 10:06:54 -0800
Craig James <craig_james(at)emolecules(dot)com> wrote:

> 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.

This scares me... You lose WAL you are a goner. Combine your OS and
WAL into a RAID 1.

Sincerely,

Joshua D. Drake

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