Can i pause VM's while power-cycling iscsi storage array

Question

Unfortunately I may have to power-cycle my storage array.

In the context of using KVM with libvirt managing the Virtual Machines where i need to power-cycle the storage array, is it possible or even advisable to :

pause the VM's
flush and turn off multipath
log out of iSCSI sessions
update and power-cycle storage array.

then follow the reverse course of

re-establish iISCSI sessions
restore multipathing
resume VM's

Any advice is welcome.

Note, that this *is* possible in VMWare. I was hoping for an answer that would address this in KVM as well. — ewwhite, Mar 14 '12 at 19:59
Reason number 52634 why VMWare is in all ways superior to KVM. — Basil, Mar 14 '12 at 21:21

score 7 · Accepted Answer · answered Mar 14 '12 at 19:20

7

I would recommend powering everything down when you power cycle the array. That way you are completely sure that everything is flushed correctly.

The additional outage time sucks, but when it comes to downing the storage array I don't screw around with shortcuts.

answered Mar 14 '12 at 19:20

mrdenny

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Sounds good. not my favorite thing to do, but i think you're right. – janos erdelyi Mar 14 '12 at 19:58

score 3 · Answer 2 · answered Mar 14 '12 at 20:17

Pause means migrating the VM into a file, and then reloading it from that file. You need to make sure the file is on the local storage and not on the SAN. And before pausing, I'd also try and quiesce the VM, the the application you are using allows it.

Can i pause VM's while power-cycling iscsi storage array

2 Answers2