LinuxQuestions.org - AoE (ATA over Ethernet) Performance Problem

Hi,

Not sure if I should post this in the Networking Forum... anyway...

I've set up AoE on a private gigabit network between 2 servers both equipped with gigabit interfaces. Both systems are fairly decent and recent server and running Fedora FC 11 x64.

My problem is that once mounted on the AoE initiator, the volume becomes very slow!

I can reach raw write performance of about 2.5 Gb/s locally on the AoE target, if I mount the AoE volume locally:

[root@aoe_target_priv mnt]# dd if=/dev/zero of=/mnt/1g bs=1M count=1k
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 3.224 s, 333 MB/s

Once mounted on the AoE initiator, the write speed goes down to only 180 Mb/s:

[root@aoe_initiator_priv ~]# dd if=/dev/zero of=/aoe/raid-01/1g bs=1M count=1k
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 36.093 s, 29.7 MB/s

A quick network test with ttcp tells me the throughput is about 620 Mb/s:

[root@aoe_target_priv ~]# ttcp -t -s -p 2000 -l 1000000 aoe_initiator_priv
ttcp-t: buflen=1000000, nbuf=2048, align=16384/0, port=2000 tcp -> barbados_priv
ttcp-t: socket
ttcp-t: connect
ttcp-t: 2048000000 bytes in 25.44 real seconds = 78630.84 KB/sec +++
ttcp-t: 2048 I/O calls, msec/call = 12.72, calls/sec = 80.52
ttcp-t: 0.0user 8.6sys 0:25real 34% 0i+0d 0maxrss 0+245pf 4533+1171csw

So I guess the network is not the bottleneck here. Any idea on how to tune AoE?

Thanks a lot for your help!