Re: Deploying PostgreSQL on CentOS with SSD and Hardware RAID

On 11/05/13 02:25, Merlin Moncure wrote:
> On Fri, May 10, 2013 at 11:11 AM, Evan D. Hoffman
> <evandhoffman(at)gmail(dot)com> wrote:
>> Not sure of your space requirements, but I'd think a RAID 10 of 8x or more
>> Samsung 840 Pro 256/512 GB would be the best value. Using a simple mirror
>> won't get you the reliability that you want since heavy writing will burn
>> the drives out over time, and if you're writing the exact same content to
>> both drives, they could likely fail at the same time. Regardless of the
>> underlying hardware you should still follow best practices for provisioning
>> disks, and raid 10 is the way to go. I don't know what your budget is
>> though. Anyway, mirrored SSD will probably work fine, but I'd avoid using
>> just two drives for the reasons above. I'd suggest at least testing RAID 5
>> or something else to spread the load around. Personally, I think the ideal
>> configuration would be a RAID 10 of at least 8 disks plus 1 hot spare. The
>> Samsung 840 Pro 256 GB are frequently $200 on sale at Newegg. YMMV but they
>> are amazing drives.
>
> Samsung 840 has no power loss protection and is therefore useless for
> database use IMO unless you don't care about data safety and/or are
> implementing redundancy via some other method (say, by synchronous
> replication).

I believe the original poster was referring to the "840 Pro" model; that
model does include a "supercap" for power loss protection.

-Toby