[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [dm-devel] dm-multipath has great throughput but we'd like more!



On Thu, May 18, 2006 at 08:44:14AM +0100, Bob Gautier wrote:
The card is a 64-bit PCI-X, so I don't think the bus is the bottleneck,
and anyway the vendor specifies a maximum throughput of 200Mbyte/s per
card.

The disk array does not appear to be the bottleneck because we get
200Mbyte/s when we use *two* HBAs in load-balanced mode.

The question is really about why we only see O(100Mbyte/s) with one HBA
when we can achieve O(200MByte/s) with two cards, given that one card
should be able to achieve that throughput.

I don't think the method of producing the traffic (bonnie++ or something
else) should be relevant but if it were that would be very interesting
for the benchmark authors!

The storage is an HDS 9980 (I think?)
i am not an expert with Hitachi storages,
anyway
does each hba map to a different controller on the storage?
do you have some statistics on disk usage from the storage side?

L.

--
Luca Berra -- bluca comedia it
       Communication Media & Services S.r.l.
/"\
\ /     ASCII RIBBON CAMPAIGN
 X        AGAINST HTML MAIL
/ \


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]