On 04/27/2011 11:33 PM, HSIEN-WEN CHU wrote:
When database files are on a VxFS filesystem, performance can be significantly improved by setting the VX_CONCURRENT cache advisory on the file according to vxfs document,
That won't improve performance, and it's not safe either. VX_CONCURRENT switches the filesystem to use direct I/O. That's usually slower for PostgreSQL. And it introduces some requirements for both block alignment and the application avoiding overlapping writes. PostgreSQL doesn't do either, so I wouldn't expect it to be compatible with VX_CONCURRENT.
-- Greg Smith 2ndQuadrant US greg@xxxxxxxxxxxxxxx Baltimore, MD PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
