On Sun, Mar 4, 2012 at 12:45 PM, Andy Colson <andy@xxxxxxxxxxxxxxx> wrote: > On 03/04/2012 03:58 AM, Rory Campbell-Lange wrote: >> >> I'd be grateful for advice on specifying the new server >> >> providing about 230GB of usable storage, 150GB of which is on an LV >> providing reconfigurable space for the databases which are served off an >> XFS formatted volume. >> > > Do you mean LVM? I've heard that LVM limits IO, so if you want full speed > you might wanna drop LVM. (And XFS supports increasing fs size, and when > are you ever really gonna want to decrease fs size?). It certainly did in the past, I don't know if anyone's done any conclusive testing on in recently, but circa 2005 to 2008 we were running RHEL 4 and LVM limited the machine by quite a bit, with max sequential throughput dropping off by 50% or more on bigger ios subsystems. I.e. a 600MB/s system would be lucky to hit 300MB/s with a LV on top. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
