[NTLUG:Discuss] Disk performance.

[Steve Baker]

Dan Carlson wrote:
> 
> On my Celeron 500 MHz system using Linux's software RAID support I get the
> following:
> 
> 16.84 MB/sec on a two drive RAID 1 array on two 7200 rpm drives UDMA 66
> drives running as UDMA 33.
> 
> 18.55 MB/sec on a four drive RAID 5 array on two 5400 rpm UDMA 33 drives and
> two 7200 rpm UDMA 66 drives running as UDMA 33.
> 
> These numbers are obtained using hdparm -t on the md RAID partitions.

OK - that's encouraging.  My test (I just realised) is producing 5Mbyte/sec
AFTER decompression - but my files have about a 2:1 compression ratio - so
I was really only getting about 2.5Mbyte/sec at the disk drive.

I didn't know about hdparm - but it tells me my drive is managing about
3.77Mbyte/sec.

It looks like a simple software RAID is the answer I'm looking for then.

I'm going to need lots of disk drives in any case (there are hundreds of
Gigs of data in this machine) - so software RAID sounds like the answer.

> Have fun, and keep us posted on the results.

Yes - I'll do that - many thanks, this was just the kind of confirmation
I was hoping for.

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