Re: LIO performance

[Nicholas A. Bellinger]

On Sun, 2008-11-09 at 03:11 -0800, learner.study wrote:
> Hello:
>
> Are there some parameters that can be tuned to increase LIO iSCSI
> target performance?
> I'm using MS initiator and pumping traffic using IOMETER and seeing
> ~720Mbps with 32k block size on a 1G link.

Are you able to saturate the link when you jump to a larger blocksize..?

Also, if your 1 Gb/sec NICs and Switching hardware supports it, you can
try using a 9000 or greater byte MTU (Jumbo Frames). This reduces the
amount of interrupts that the host CPUs have to handle on both machines.

Also, enabling hardware TCP/IP checksumming in your NIC hardware can
help. Some Intel NIC hardware also supports increasing the amount of
RxDescriptors and TxDescriptors (they are kernel module parameters) and
this is helped me while doing 4x 1 Gb/sec MC/S tests with Linux and MSFT
iSCSI Initiators to LIO-Target over the years.

Also, I would recommend getting your setup stable first, and figure out
what is going on with iSCSI session recovery (reconnects). :-)

--nab

>
> Thanks,
> Vishal.
> >