On Mon, 26 Jan 2009, M. Edward (Ed) Borasky wrote:
Is there a howto somewhere on disabling this on a Seagate Barracuda?
http://inferno.slug.org/cgi-bin/wiki?Western_Digital_NCQ is a good discussion of disabling NCQ support under Linux (both in user-space and directly in the kernel itself). A good summary of the problems with the WD NCQ support alluded to there are at http://lkml.org/lkml/2007/4/3/159 if you're curious.
It's a tough time to be picking up inexpensive consumer SATA disks right now. Seagate's drive reliability has been falling hard the last couple of years, but all the WD drives I've started trying out instead have just awful firmware. At last they're all cheap I guess.
P.S. I have several of the same basic Seagate drive you have (160GB, even bought at CompUSA!) and would expect at least 2-3X better pgbench results than you're seeing. I realized that I've never actually run that test without first tweaking the postgresql.conf (shared_buffers,checkpoint_segments) so that may be part of it. One of my systems here has just one of those disk in it, next time I boot that up I'll see what results I get with an untuned config.
-- * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
