[Etherboot-discuss] iSCSI slowness

[Thomas M. <tho...@gm...>]

Hi everyone,
I'm experiencing a slowness when I iSCSI boot DOS and run scandisk.

I'm using the latest gPXE-git version and was able to reproduce the
issue with rtl8139, r8169 and eepro100 cards in the client. I was
using a D-Link DGE-530T gigabit card in the server(linux driver is
skge). The 2 machines were directly connected using a Cat5e 4-pair
crossover cable.
Using a via-rhine card in the server or keeping the skge card, but
putting a switch in between those two PCs fixes the problem.
When experiencing the slowness, it seems that scandisk is stuck for a
short moment and continues again. It gets stuck about every other
second.

Usually I'd say it's some kind of hardware problem, because changing
the server network card or using a switch fixes the problem. I'm
writing to the list anyway because HTTP transfers with the same
setup(skge card in the server, same crossover cable, no switch, any of
the 3 mentioned cards in the client) are really fast. I usually get
around 11MB/sec for HTTP transfers(measured with the time command in
gPXE).
mdc seemed to experience similar(the same?) problems also when testing
some driver changes I made. As far as I know he was using a switch,
and both the server and client network cards were eepro100 cards.

I'm using IET as iscsi target, iscsid version 0.4.16

I have two packet captures, one for the slow transfer and one for the
fast transfer at http://etherboot.org/share/meteger/dumps.tar.gz
Please let me know if you need any additional information.

Thanks in advance for any answers
Thomas Miletich