XenServer 5.5 with iSCSI Storage on Open-E DSS / Chelsio 10G network card

If you experience random VM freezes lasting a few seconds, it would be good idea to check if the XenServer has a valid network card driver.

As a result you may see the following errors:

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2011-03-28 12:06:16 Kernel.Info 172.16.100.101 kernel: connection16:0: iscsi: detected conn error (1011)

2011-03-28 12:06:17 Daemon.Warning 172.16.100.101 iscsid: Kernel reported iSCSI connection 16:0 error (1011) state (3)

2011-03-28 12:06:19 Kernel.Info 172.16.100.101 kernel: iscsi: host reset succeeded

2011-03-28 12:06:20 Daemon.Warning 172.16.100.101 iscsid: connection16:0 is operational after recovery (2 attempts)

2011-03-28 12:06:29 Kernel.Error 172.16.100.101 kernel: sd 18:0:0:0: timing out command, waited 360s

2011-03-28 12:06:29 Kernel.Info 172.16.100.101 kernel: sd 18:0:0:0: SCSI error: return code = 0x06050000

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XenServer 5.5 Update 2 doesn't contain driver for Chelsio 10G network card, so an update to XenServer version 5.6 which have it, is strongly recommended.

This KB article is based on CU post on Citrix forum:

http://forums.citrix.com/thread.jspa?threadID=284603&tstart=0