Re: Performance while loading data and indexing

scott.marlowe wrote:

>(snippage)
>I take exception to this. RAID5 is a great choice for most folks.
>
>
I agree - certainly RAID5 *used* to be rather sad, but modern cards have
improved this no end on the hardware side - e.g.

I recently benchmarked a 3Ware 8x card on a system with 4 x 15000 rpm
Maxtor 70Gb drives and achieved 120 Mb/s for (8K) reads and 60 Mb/s for
(8K) writes using RAID5. I used Redhat 7.3 + ext2. The benchmarking
program was Bonnie.

Given that the performance of a single disk was ~30 Mb/s for reads and
writes, I felt this was quite a good result ! ( Other cards I had tried
previously struggled to maintain 1/2 the write rate of a single disk in
such a configuration).

As for software RAID5, I have not tried it out.

Of course I could not get 60Mb/s while COPYing data into Postgres...
typically cpu seemed to be the bottleneck in this case (what was the
actual write rate? I hear you asking..err.. cant recall I'm afraid..
must try it out again )

cheers

Mark