Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller

On Fri, Feb 6, 2009 at 2:04 AM, Matt Burke <mattblists(at)icritical(dot)com> wrote:
> Scott Carey wrote:
>> You probably don't want a single array with more than 32 drives anyway,
>> its almost always better to start carving out chunks and using software
>> raid 0 or 1 on top of that for various reasons. I wouldn't put more than
>> 16 drives in one array on any of these RAID cards, they're just not
>> optimized for really big arrays and tend to fade between 6 to 16 in one
>> array, depending on the quality.
>
> This is what I'm looking at now. The server I'm working on at the moment
> currently has a PERC6/e and 3xMD1000s which needs to be tested in a few
> setups. I need to code a benchmarker yet (I haven't found one yet that
> can come close to replicating our DB usage patterns), but I intend to try:
>
> 1. 3x h/w RAID10 (one per shelf), sofware RAID0

Should work pretty well.

> 2. lots x h/w RAID1, software RAID0 if the PERC will let me create
> enough arrays

I don't recall the max number arrays. I'm betting it's less than that.

> 3. Pure s/w RAID10 if I can convince the PERC to let the OS see the disks

Look for JBOD mode.

> 4. 2x h/w RAID30, software RAID0
>
> I'm not holding much hope out for the last one :)

Me either. :)