Re: Deploying PostgreSQL on CentOS with SSD and Hardware RAID

From: "Evan D(dot) Hoffman" <evandhoffman(at)gmail(dot)com>
To: David Boreham <david_list(at)boreham(dot)org>
Cc: Postgresql Mailing List <pgsql-general(at)postgresql(dot)org>
Subject: Re: Deploying PostgreSQL on CentOS with SSD and Hardware RAID
Date: 2013-05-10 16:11:07
Message-ID: CABRB-LtSwDGUL3gmr9xh-4MvfzSoSD3OHOPW=F3Dpe5oU_0xVg@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

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.

On Fri, May 10, 2013 at 11:25 AM, David Boreham <david_list(at)boreham(dot)org>wrote:

> On 5/10/2013 9:19 AM, Matt Brock wrote:
>
>> After googling this for a while, it seems that High Endurance MLC is only
>> starting to rival SLC for endurance and write performance in the very
>> latest, cutting-edge hardware. In general, though, it seems it would be
>> fair to say that SLCs are still a better bet for databases than MLC?
>>
>
> I've never looked at SLC drives in the past few years and don't know
> anyone who uses them these days.
>
>
>
>> The number and capacity of drives is small in this instance, and the
>> price difference between the two for HP SSDs isn't very wide, so cost isn't
>> really an issue. We just want to use whichever is better for the database.
>>
>>
>>
> Could you post some specific drive models please ? HP probably doesn't
> make the drives, and it really helps to know what devices you're using
> since they are not nearly as generic in behavior and features as magnetic
> drives.
>
>
>
>
>
>
>
>
>
> --
> Sent via pgsql-general mailing list (pgsql-general(at)postgresql(dot)org)
> To make changes to your subscription:
> http://www.postgresql.org/**mailpref/pgsql-general<http://www.postgresql.org/mailpref/pgsql-general>
>

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Tom Lane 2013-05-10 16:19:11 Re: authentication/privileges
Previous Message Larry Rosenman 2013-05-10 16:01:15 Re: LONG delete with LOTS of FK's