So, I've been playing with iscsi autofailover. It's awesome, and easy to use, if you follow the step-by-step how-to pdf (the how-to is easier to follow than the white paper). I have some more aggressive timings in failing over, so that windows clients won't time out during a failover (some windows systems will timeout if attached storage doesn't get back within like half a minute).
Failover--from unplugging a network cable until the logs say failover is complete--takes just under 30 seconds. While playing music in windows on the iscsi volume that is failed over, there's a pause for a few seconds, but then the music continues without any errors.
I have:
warn time: 2000ms
dead time: 4000ms
init time: 5000ms
Keep alive time: 500ms
It could be that failover is a little faster than 28 seconds, but I'm not sure. Is data being accessed on the secondary system when the logs on the secondary say "iSCSI Failover: Secondary node: Acquiring resources. Node is now active."? If so, then failover takes only 16 seconds.
What are the limitations of iSCSI failover? Can you add new volumes/tasks to be failed over without disconnecting your clients? Can you update one half of the cluster to a newer version of open-e dss and then failover and upgrade the other half? Does storage expansion work? What sort of performance are people getting when using autofailover?
BTW, if using a SAN, whether iscsi or Fibre Channel, on a Windows platform, it's recommended to add or change the parameter (of data type REG-DWORD) "TimeOutValue" in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Disk to 60 (decimal) or more. This is the time in seconds to wait for the storage to return data before Windows starts generating errors. This should be at least twice your expected failover time. So, it's wise to set TimeOutValue to 180 or more.
(more info on this is found here: http://publib.boulder.ibm.com/infoce...ut_198ovw.html )