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