On Thu, Dec 5, 2013 at 8:16 AM, Skarsol <skarsol@xxxxxxxxx> wrote: > psql (PostgreSQL) 9.2.5 > Red Hat Enterprise Linux Server release 6.4 (Santiago) > Linux 2.6.32-358.6.1.el6.x86_64 #1 SMP Fri Mar 29 16:51:51 EDT 2013 x86_64 > x86_64 x86_64 GNU/Linux > All relevant filesystems are ext4 > > Changes from defaults: > max_connections = 500 > shared_buffers = 32000MB > temp_buffers = 24MB > work_mem = 1GB > maintenance_work_mem = 5GB > wal_level = archive > wal_buffers = 16MB > checkpoint_completion_target = 0.9 > archive_mode = on > archive_command = 'test ! -f /databases/pg_archive/db/%f && cp %p > /databases/pg_archive/db/%f' > effective_cache_size = 64000MB > default_statistics_target = 5000 > log_checkpoints = on > stats_temp_directory = '/tmp/pgstat' OK I'd make the following changes. 1: Drop shared_buffers to something like 1000MB 2: drop work_mem to 16MB or so. 1GB is pathological, as it can make the machine run out of memory quite fast. 3: drop max_connections to 100 or so. if you really need 500 conns, then work_mem of 1G is that much worse. Next, move pg_xlog OFF the SSDs and back onto spinning media and put your data/base dir on the SSDs. SSDs aren't much faster, if at all, for pg_xlog, but are much much faster for data/base files. Also changing the io schduler for the SSDs to noop: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/block/switching-sched.txt?id=HEAD -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
