stopping iscsi i/o

[Chasethegrey]

Is there a way to stop I/O to an iSCSI storage server and then reconnect to those LUN's without powering off and on the ESXi hosts? We need to do maintenance on the storage server but starting up the ESXi servers take a long time (~20-30 minutes) because of (I think) a bug in the version of ESXi 5 that we are running that waits a long time for dead iSCSI targets to respond.

Is it enough to just put the ESXi servers into maintenance mode and will they successfully reconnect to a iSCSI server that has been re-powered when taken out of maintenance mode?

Thanks!

[Dave_Mishchenko · Accepted solution]

I think you'd be fine to put the hosts in maintenance mode and then rescan your storage after the SAN is back up.  You'll generate a bunch of alerts when the SAN goes down, but it's probably easier than rebooting.   The bug you describe with a work around to minimize impact is described here - http://kb.vmware.com/kb/2007108.

[rpotru]

Yes. You would be fine. I have done this many times. Keep the host in maintanace mode and do the maintanace work on iSCSI server.

Exit the MM of host and storage will be automatically seen by the host. I don't see any issues.

[Chasethegrey]

This is great. Thank you so much for both of your input and the KB article of workarounds.