Does the source qtree require user access via an NFS export during the archival process? Its possible to migrate the data using either a host based or storage migration process however at some point you will require an outage to remount the data on the NFS client.
If you do not require user access whilst arching the qtree and assuming you don't want to perform a host based copy and want the storage array to perform to migrate the data then one "option" would be to flexclone the volume, remove the the other qtrees within the flexcloned volume then split the flexclone to a new volume resulting in a new flexvol with a single qtree within it however depending on the amount of data within your volume and the number of files this might be an inefficent method and could have a performance impact so you'd need to analyse the data before doing so.
Alternately if you do not require user access whilst archiving the qtree but you are worried about a potential performance impact on your production cluster during this process by using the above flexclone method of migration you could snapmirror the volume to DR cluster. It's possible to snapmirror the volume to a DR cluster\vserver, perform the above flexclone process in DR then snapmirror the new flexvol volume containing the single source qtree back to the production cluster and re-mount the volume to your production vserver. Whilst its possible to do this it's probably much quicker to just perform a host based migration though.
If you had a lot of data within a single qtree in a source flexvol and a few other qtrees within that flexvol and you wanted to split out the larger qtree into a new flexvol then using the flexclone method would be an appropriate. If you have lots of qtrees in flexvol of approximately equal size and you want to split out one qtree then it's definately more efficent to perform a host based migration of the source qtree into a new target flexvol and remove the source qtree from the source volume once completed.
Hope that gives you some ideas. Sorry you can't do a Qtree snapmirror anymore in cDOT as was previously available in 7-Mode.
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