I want to upgrade some controllers from ontap 8.1.2 to 8.2.3P4 . One system is snapmirror destination and 2 other controllers are the source. Now i ask myself is it enough to break the snapmirror relation then upgrade the destination controller and then the source controllers, or do i have to set snapmirror off then upgrade the destination controller and then the source controllers and then recreate the snapmirror releations?
It is recommended to turn off / disable SnapMirror on the destination to prevent SnapMirror updates running during the upgrade process. There is no need to break re-create the relationships.
I suggest the following:
Create upgrade plans for the source and destination controllers via MyAutoSupport.
Upgrade the destination controller(s) first. In a volume SnapMirror relationship the destination controller must be the same or a higher major ONTAP version than that of the source. For example, VSM from ONTAP 8.1.x to 8.2.x will work. VSM from 8.2.3 to 8.2.1 will also work, but VSM from 8.2.x to 8.1.x won't.
Run "snapmirror off" on the destination controller(s) as part of the upgrade process.
Upgrade the source controllers.
When all controllers are upgraded run "snapmirror on" on the destination controller(s).
Run "snapmirror update" or wait for the scheduled update to kick off.
the upgrade plans via autosupport are absolutely valuable when doing this type of work!
I have just done something similar with ONTAP, moving from 8.2.1 to 8.2.3P3 and just followed the guides step by step and they worked a treat and yes its best to switch off snapmirror, it says this in the guidelines.
You need to set snapmirror to off so they the relationships dont start updating during your uprgrade work. All you need to do is quiese, update and once the update is complete turn off snapmirror on source and destination.