Am 19.04.2011 11:15, schrieb Laurent Laborde:
Soft RAID1 (md) ext3
We have experimented a bit with Postgres and ext3 (with and without Linux software RAID1) and have found that since somewhere after 2.6.18, it has been prohibitively slow and causing high latencies during buffer flushes. You will probably see a significant improvement with ext4 (mkfs.ext4, not just remount as ext4, which is also possible).
Also, you need to make sure that your blocks are properly aligned with SSDs, that might explain low random I/O performance. See http://www.nuclex.org/blog/personal/80-aligning-an-ssd-on-linux and http://www.ocztechnologyforum.com/forum/showthread.php?54379-Linux-Tips-tweaks-and-alignment&p=373226&viewfull=1#post373226 for example.
Regards, Marinos -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
