Differences
This shows you the differences between two versions of the page.
hpdl385-bnx2-nic [2008/01/15 10:39] pegasus |
hpdl385-bnx2-nic [2009/05/25 00:35] |
||
---|---|---|---|
Line 1: | Line 1: | ||
- | I recently found out that drbd link between two HP DL385 machines tends to stall under high io load. Investigations turned out that tcp segmentation performed by the nic is faulty. | ||
- | Problem is easy to reproduce. You need some traffic generator (I used xinetd chargen), some traffic sink (I used nc > /dev/null) and iptraf or tcpdump. | ||
- | |||
- | After playing with ethtool -K settings I found out that tcp segmentation offload is to blame. You can turn it off simply with ethtool -K ethX tso off and bad packets magically disappear. | ||
- | |||
- | I verified this to be true with bnx2 driver version 1.4.43, 1.4.52d and 1.5.11-rh. I'll repeat tests with 1.6.7 (directly from broadcom site) in about two weeks. There are some reports that it fixes the problem. | ||
- | |||
- | Update: the fix went in just after 1.5.11, so all versions after it work properly, including 1.6.7. |