Vol Moving Volumes in a TDP Relation

A useful thing to know that you can vol move volumes in cDOT that are in a TDP (transition) relation with 7-Mode - useful if you’ve put the destination volume on the wrong node in the cluster…

Commands to vol move a volume in a TDP relation:

CLUSTER::>

snapmirror show -destination-path SVMNAME:VOLNAME
volume show -volume VOLNAME -fields aggregate
snapmirror break -destination-path SVMNAME:VOLNAME
set d
volume transition-protect -vserver SVMNAME -volume VOLNAME -is-enabled off
volume move start -vserver SVMNAME -volume VOLNAME -destination-aggregate NEW_DESTINATION_AGGR
volume move show -vserver SVMNAME -volume VOLNAME
volume transition-protect -vserver SVMNAME -volume VOLNAME -is-enabled on
snapmirror resync -destination-path SVMNAME:VOLNAME
snapmirror show -destination-path SVMNAME:VOLNAME

Checking the transition session in 7MTT CLI:

7MTTCLI>

transition update -s 7MTT_SESSION -r no
transition show -s 7MTT_SESSION -r no


Note: If you’re using 7MTT GUI, run an update from there to check all is good.

Comments

  1. This is extremely useful. Two small notes:

    - You cannot resync the snapmirror relation until after the "vol move" completes. And you'd better wait setting the transition-protect bit back, too, or "vol move show" may give confusing results (tested on ontap 9.1)

    - after you "snapmirror break", 7mtt will try to resync the relationship every few minutes, so if you don't start the "vol move" in time, it might fail because the snapmirror relationship is being resynched by 7mtt. If so, just break again and retry the vol move start.

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    Replies
    1. Hello John, thanks for the comment. It might be best to disable 7MTT if you're doing this (unfortunately, stopping the 7MTT service does mean you'd need to re-input the credentials after). Cheers, VC

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    2. Actually, I just went ahead and tried this with OnTap 9.1 and 7mtt 3.1. It works without problems, just make sure to start the vol move fast enough, as I indicated earlier.

      After the vol move completes, it's even easier with newer 7mtt, because it automatically resyncs the snapmirror. Setting the TMP bit back can be done afterwards.

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  2. I have tried this by putting 7mtt project in to test mode , then vol move , then finish testing.. so far working good .. not sure if any errors while cutover.
    Any of u experience this ?

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