I'm planning to migrate our pg db to a new machine in the next couple of weeks. The current DB has 32 GB memory; the new one will have 96 GB. It's going to be Postgres 8.2.x (we're planning to upgrade to 8.4 as part of another project) running on CentOS 5.4 or 5.5. I know the old rule of thumb that your swap partition/disk should be equal to the physical memory, but when dealing with memory sizes greater than ~16 GB that starts to seem strange to me; and now with 96 GB of physical memory I'm starting to wonder if I'd be better off forgoing swap altogether for the new database. Are there any general suggestions for swap size for a Postgres DB? I assume that paging to/from disk is something that I'd want to avoid, especially in a database (which is why I'm debating disabling it altogether), but I'm not sure what the drawbacks would be (aside from the obvious one of there being less total memory available to the system). Oracle actually has some guidelines for swap space in the installation docs - http://www.dba-oracle.com/t_server_swap_space_allocation.htm - but I don't know of anything similar for Postgres, and I don't know if/how having such a huge amount of memory affects those guidelines. 3/4 of 8 GB is 6 GB of swap, which seems reasonable; 3/4 of 96 GB is 72 GB, which strikes me as excessive. Any thoughts would be appreciated. Thanks, Evan -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
