On 3/26/10 4:57 PM, Richard Yen wrote: > I'm planning on lowering the shared_buffers to a more sane value, like 25GB (pgtune recommends this for a Mixed-purpose machine) or less (pgtune recommends 14GB for an OLTP machine). However, before I do this (and possibly resolve the issue), I was hoping to see if anyone would have an explanation for the constant reading from swap, but never writing back. Postgres does not control how swap is used. This would be an operating system issue. Leaving aside the distict possibility of a bug in handling swap (nobody seems to do it well), there's the distinct possibility that you're actually pinning more memory on the system than it has (through various processes) and it's wisely shifted some read-only files to the swap (as opposed to read-write ones). But that's a fairly handwavy guess. -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance