Re: [PERFORM] IDE x SAS RAID 0 on HP DL 380 G5 P400i controller performance problem

2010-07-20 Thread Scott Carey
If you are using ext3, your performance on the RAID card may also improve if the postgres xlog is not on the same partition as the data. Otherwise, for every transaction commit, all of the data on the whole partition will have to be sync()'d not just the xlog. Also, what is the performance dif

Re: [PERFORM] IDE x SAS RAID 0 on HP DL 380 G5 P400i controller performance problem

2010-07-19 Thread Daniel Ferreira de Lima
> That said, a look into the write-caching+BBU policy on your controller is > worthwhile. If you're running this application successfully on some > hardware but not others, that could be a source for the difference. > I think it's really a BBU/BBWC problem. The tests that we made in the lab with

Re: [PERFORM] IDE x SAS RAID 0 on HP DL 380 G5 P400i controller performance problem

2010-07-19 Thread Greg Smith
Daniel Ferreira de Lima wrote: > **Both with Linux Kernel 2 .4.37.9 and Postgresql 7.2** Wow. You really need to upgrade. Yes, but unfortunately, actually it's impossible and economically inviable... Generally, getting good performance out of PostgreSQL 7.2 is also impossible

Re: [PERFORM] IDE x SAS RAID 0 on HP DL 380 G5 P400i controller performance problem

2010-07-19 Thread Daniel Ferreira de Lima
> > **Both with Linux Kernel 2 .4.37.9 and Postgresql 7.2** > > Wow. You really need to upgrade. > Yes, but unfortunately, actually it's impossible and economically inviable... > > Under a insertion test we get a performance of 2.5 secs under 2000 > > inserts (table with a single char(50) col

Re: [PERFORM] IDE x SAS RAID 0 on HP DL 380 G5 P400i controller performance problem

2010-07-19 Thread Kevin Grittner
Daniel Ferreira de Lima wrote: > **Both with Linux Kernel 2 .4.37.9 and Postgresql 7.2** Wow. You really need to upgrade. > Under a insertion test we get a performance of 2.5 secs under 2000 > inserts (table with a single char(50) column) in the IDE disk. > And 500GB RAID 0 (4 disks!) and 3

[PERFORM] IDE x SAS RAID 0 on HP DL 380 G5 P400i controller performance problem

2010-07-19 Thread Daniel Ferreira de Lima
Hi people, I have a particular performance problem under a system installed. In the lab I have an old Microside + Dual Core machine 1GB RAM with 40gb HD IDE and a newer machine HP DL 380 G5 4GB RAM and 500GB SAS under RAID 0 (4 disks) P400i Smart Array Controller. **Both with Linux Kernel 2 .4.3