Ok, a quick view on the system, and some things that may be important to note: > Our deployment machine is a Dell PowerEdge T420 with a Perc H710 RAID > controller configured in this way: > > * VD0: two 15k SAS disks (ext4, OS partition, WAL partition, > RAID1) > * VD1: ten 10k SAS disks (XFS, Postgres data partition, RAID5) > Well...usually RAID5 have the worst performance in writing...EVER!!! Have you tested this in another raid configuration? RAID10 is usually the best bet. > > > This system has the following configuration: > > * Ubuntu 14.04.2 LTS (GNU/Linux 3.13.0-48-generic x86_64) > * 128GB RAM (DDR3, 8x16GB @1600Mhz) > * two Intel Xeon E5-2640 v2 @2Ghz > * Dell Perc H710 with 512MB RAM (Write cache: "WriteBack", Read > cache: "ReadAhead", Disk cache: "disabled"): > * VD0 (OS and WAL partition): two 15k SAS disks (ext4, RAID1) > * VD1 (Postgres data partition): ten 10k SAS disks (XFS, > RAID5) > * PostgreSQL 9.4 (updated to the latest available version) > * moved pg_stat_tmp to RAM disk > > [...]> versions. > You did not mention any "postgres" configuration at all. If you let the default checkpoint_segments=3, that would be an IO hell for your disk controler...and the RAID5 making things worst...Can you show us the values of: checkpoint_segments shared_buffers work_mem maintenance_work_mem effective_io_concurrency I would start from there, few changes, and check again. I would change the RAID first of all things, and try those tests again. Cheers. Gerardo -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
