From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bob Gautier <rgautier@redhat.com>
Subject: dm-multipath has great throughput but we'd like more!
Date: Thu, 18 May 2006 08:05:28 +0100
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	device-mapper development <dm-devel@redhat.com>
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Yesterday my client was testing of multipath load balancing and failover
on a system running ext3 on a logical volume which comprises about ten
SAN LUNs all reached using multipath in multibus mode over two QL2340
HBAs.

On the one hand, the client is very impressed: running bonnie++
(inspired by Ronan's GFS v VxFS example) we get just over 200Mbyte/s
over the two HBAs, and when we pull a link we get about 120MByte/s.

The throughput and failover response times are better than the client
has ever seen, but we're wondering why we are not seeing higher
throughput per-HBA -- the QL2340 datasheet says it should manage
200Mbyte/s and all switches etc. run at 2GBps.

Any ideas?

Bob Gautier
+44 7921 700996