Hardware: 48 core AMD Magny Cours (4x12) 128G 1333MHz memory 34 15k6 drives, 2 hot spares, rest in RAID-1 pairs, 1 set for OS, 4 for pg_xlog, rest for /data/base LSI 8888 RAID controller OS: Ubuntu 10.04 uname -a Linux bigassdbserver 2.6.32-24-generic #38-Ubuntu SMP Mon Jul 5 09:20:59 UTC 2010 x86_64 GNU/Linux scheduler = noop for all drive sets. Settings for sysctl.conf: vm.zone_reclaim_mode = 0 kernel.shmmax = 33554432000 kernel.shmall = 2097152000 kernel.shmmni = 4096 vm.swappiness = 0 vm.dirty_ratio = 2 vm.dirty_background_ratio = 1 $ free total used free shared buffers cached Mem: 131651412 104986524 26664888 0 910804 91170764 -/+ buffers/cache: 12904956 118746456 Swap: 0 0 0 (swap is now off with sudo swapoff -a, it fixed the problem) It's twin, the read slave, looks like this: $ free total used free shared buffers cached Mem: 131651412 110364700 21286712 0 702144 96771656 -/+ buffers/cache: 12890900 118760512 Swap: 25388024 940 25387084 So, this morning, the machine goes into 100% swap usage. four kswapds are running at 100% CPU in mostly D state. Load climbs to 300. Server gets a little slow. Swapoff -a fixes it. This makes no sense to me. The machine had 90G+ in kernel cache, and was NOT running out of memory in any way. Swappiness is 0. Any advice on this, reporting it to the kernel guys etc welcome. -- To understand recursion, one must first understand recursion. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general