On Fri, Jul 6, 2012 at 8:51 PM, ach <alanchi...@gmail.com> wrote: > > My fastest postgresql servers have everything on one raid10, using 16 or > > 20 15000 rpm SAS2 drives on a 1gb flash-backed cache controller. > > Thank you - that affirms what'd been my own growing supposition, and the > plan > > > why? > > Really? ...Well, I mean, I'd just been going with what I'd seen asserted > as > the solid baseline position: WAL should be on its own separate drive, > devoid of any interference and/or interruption other than just writing WAL. > To see that challenged is surprising; are you saying my interpretation on > that point would be incorrect, and that assumption would be wrong? > > Thank you again for your feedback! > > I wouldn't make any assumptions, and benchmark various configurations using your hardware and your data usage pattern. Sometimes "common knowledge" doesn't apply to your specific problem.
http://www.slideshare.net/selenamarie/what-assumptions-make-filesystem-io-from-a-database-perspective
