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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 :

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

then follow the reverse course of

  1. re-establish iISCSI sessions
  2. restore multipathing
  3. resume VM's

Any advice is welcome.

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2  
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

2 Answers 2

up vote 7 down vote accepted

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.

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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

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.

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