Re: Setup of four 15k SAS disk with LSI raid controller

Its better to split WAL segments and data just because these two have
different io requirements and because its easier to measure and tune things
if you have them on different disks.

Vasilis Ventirozos

On Wed, Mar 13, 2013 at 8:37 PM, Niels Kristian Schjødt <
nielskristian(at)autouncle(dot)com> wrote:

> Den 13/03/2013 kl. 19.15 skrev Vasilis Ventirozos <v(dot)ventirozos(at)gmail(dot)com
> >:
>
> raid0 tends to linear scaling so 3 of them should give something close to
> 300% increased write speed. So i would say 1. but make sure you test your
> configuration as soon as you can with bonnie++ or something similar
>
> On Wed, Mar 13, 2013 at 7:43 PM, Niels Kristian Schjødt <
> nielskristian(at)autouncle(dot)com> wrote:
>
>> I have a server with 32GB ram, one intel E3-1245 and four 15k SAS disks
>> with a BB LSI MegaRaid controller. I wan't the optimal performance for my
>> server, which will be pretty write heavy at times, and less optimized for
>> redundancy, as my data is not very crucial and I will be running a
>> streaming replication along side.
>>
>> Now what would you prefer:
>>
>> 1) 3 disks in RAID 0 containing PGDATA + 1 containing SYSTEM and WAL
>> 2) All four in RAID 10 containing both PGDATA, SYSTEM AND WAL
>> 3) 2 disks in RAID 1 containing PGDATA + 2 disks in RAID 1 containing
>> SYSTEM and WAL
>> 4) Something different?
>>
> A 5. option could also be to simply have all 4 disk in a RAID 0 containing
> all PGDATA, SYSTEM and WAL
>
>
>>
>>
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