Thanks. Kernel is: 3.5.0-36-generic #57~precise1-Ubuntu Also - xlog is on ext4; db partition is zfs (on top of hardware RAID1+0). Regards, Steve ---------------------------------------- > From: ilya.kosmodemiansky@xxxxxxxxxxxxxxxxxxxxxxxxx > Date: Wed, 18 Mar 2015 13:13:36 +0100 > Subject: Re: Very slow checkpoints > To: steven.jones1201@xxxxxxxxxxx > CC: pgsql-performance@xxxxxxxxxxxxxx > > On Wed, Mar 18, 2015 at 12:58 PM, Steven Jones > <steven.jones1201@xxxxxxxxxxx> wrote: >> Yes BBU is on the controller; 1024Mb. It is a HP P410i controller, with write caching turned on the controller; off on disk level. > > > vm.dirty_background_bytes=67108864 and vm.dirty_bytes=536870912 looks > resonable for 512MB BBU, you can calculate them for 1024 or > recalculate them for dirty_background_ratio > > By the way, which kernel do you use? > >> We don't at this stage have any graphs, but we will set it up over the next 24hrs at least. > > Do not forget to have iostat statistics on them, at least latency, > %iowait and %util, such parameters are very helpful. > > And I am always suspicious about zfs under heavy writes. It is > reliable and quite comfortable in terms of configuration, but for > speed ext4 or xfs with disabled barrier looks more reasonable > >>> >>> -- >>> Ilya Kosmodemiansky, >>> >>> PostgreSQL-Consulting.com >>> tel. +14084142500 >>> cell. +4915144336040 >>> ik@xxxxxxxxxxxxxxxxxxxxxxxxx >>> >>> >>> -- >>> Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) >>> To make changes to your subscription: >>> http://www.postgresql.org/mailpref/pgsql-performance >> > > > > -- > Ilya Kosmodemiansky, > > PostgreSQL-Consulting.com > tel. +14084142500 > cell. +4915144336040 > ik@xxxxxxxxxxxxxxxxxxxxxxxxx > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
