Re: Advice configuring ServeRAID 8k for performance

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thursday, August 05, 2010, Mark Kirkwood <mark.kirkwood@xxxxxxxxxxxxxxx> 
wrote:
> Normally I'd agree with the others and recommend RAID10 - but you say
> you have an OLAP workload - if it is *heavily* read biased you may get
> better performance with RAID5 (more effective disks to read from).
> Having said that, your sequential read performance right now is pretty
> low (151 MB/s  - should be double this), which may point to an issue
> with this controller. Unfortunately this *may* be important for an OLAP
> workload (seq scans of big tables).

Probably a low (default) readahead limitation. ext3 doesn't help but it can 
usually get up over 400MB/sec. Doubt it's the controller.

-- 
"No animals were harmed in the recording of this episode. We tried but that 
damn monkey was just too fast."

-- 
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance


[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux