Re: Postgres for a "data warehouse", 5-10 TB

On Sun, Sep 11, 2011 at 4:21 PM, Igor Chudov <ichudov@gmail.com> wrote:
> Quantitatively, what would you say is the write speed difference between
> RAID 10 and RAID 6?

https://support.nstein.com/blog/archives/73

There you can see a comparison with 4 drives, and raid 10 is twice as fast.
Since raid 5/6 doesn't scale write performance at all (it performs as
a single drive), it's quite expected. 12 drives would probably be
around 6 times as fast as raid 6.

You definitely should do some benchmarks to confirm, though.

And Andy is right, you'll have a lot less space. If raid 10 doesn't
give you enough room, just leave two spare drives for a raid 0
temporary partition. That will be at least twice as fast as doing
temporary tables on the raid 6.

You'll obviously have to get creative, tons of options.