I'm writing in regards to the performance with open-iscsi on a
10gbe network. On your website you posted performance results
indicating you reached read and write speeds of 450 MegaBytes per

In our environment we use Myricom dual channel 10gbe network cards on
a gentoo linux system connected via fiber to a 10gbe interfaced SAN
with a raid 0 volume mounted with 4 15000rpm SAS drives.
Unfortunately, the maximum speed we are acheiving is 94 MB/s. We do
know that the network interfaces can stream data at 822MB/s (results
obtained with netperf). we know that local read performance on the
disks is 480MB/s. When using netcat or direct tcp/ip connection we get
speeds in this range, however when we connect a volume via the iscsi
protocol using the open-iscsi initiator we drop to 94MB/s(best result.
Obtained with bonnie++ and dd).

We were wondering if you would have any recommendations in terms of
configuring the initiator or perhaps the linux system to achieve
higher throughput.
We have also set the the interfaces on both ends to jumbo frames (mtu
9000). We have also modified sysctl parameters to look as follows :

net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
net.core.netdev_max_backlog = 250000

Any help would greatly be appreciated,
Thank you for your time and  your work.


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