Re: Deploying PostgreSQL on CentOS with SSD and Hardware RAID

On Sun, May 19, 2013 at 8:07 PM, Toby Corkindale
<toby(dot)corkindale(at)strategicdata(dot)com(dot)au> wrote:
> 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.

got a source for that? I couldn't verify that after some googling.

merlin