Re: RAID card recommendation

On 11/24/09 11:13 AM, "Scott Marlowe" <scott(dot)marlowe(at)gmail(dot)com> wrote:

>
> They get good reviews as well. Both manufacturers have their "star"
> performers, and their "utility" or work group class controllers. For
> what you're doing the areca 12xx or 3ware 95xx series should do fine.
>

-1 to 3ware's SATA solutions

3ware 95xx and 96xx had performance somewhere between PERC 5 (horrid) and
PERC 6 (mediocre) when I tested them with large SATA drives with RAID 10.
Haven't tried raid 6 or 5. Haven't tried the "SA" model that supports SAS.
When a competing card (Areca or Adaptec) gets 3x the sequential throughput
on an 8 disk RAID 10 and only catches up to be 60% the speed after heavy
tuning of readahead value, there's something wrong.
Random access throughput doesn't suffer like that however -- but its nice
when the I/O can sequential scan faser than postgres can read the tuples.

> As far as drives go we've been really happy with WD of late, they make
> large enterprise class SATA drives that don't pull a lot of power
> (green series) and fast SATA drives that pull a bit more but are
> faster (black series). We've used both and are quite happy with each.
> We use a pair of blacks to build slony read slaves and they're very
> fast, with write speeds of ~100MB/second and read speeds double that
> in linux under sw RAID-1
>