On Fri, Jul 15, 2011 at 12:34 AM, chris <chri...@gmx.net> wrote: > I was thinking to put the WAL and the indexes on the local disks, and > the rest on the SAN. If funds allow, we might downgrade the disks to > SATA and add a 50 GB SATA SSD for the WAL (SAS/SATA mixup not possible).
Just to add to the conversation, there's no real advantage to putting WAL on SSD. Indexes can benefit from them, but WAL is mosty seqwuential throughput and for that a pair of SATA 1TB drives at 7200RPM work just fine for most folks. For example, in one big server we're running we have 24 drives in a RAID-10 for the /data/base dir with 4 drives in a RAID-10 for pg_xlog, and those 4 drives tend to have the same io util % under iostat as the 24 drives under normal usage. It takes a special kind of load (lots of inserts happening in large transactions quickly) for the 4 drive RAID-10 to have more than 50% util ever. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
