topic Re: SnapMirror Resync Procedure in ONTAP Discussions

SnapMirror Resync Procedure

nicholsongc — Wed, 04 Jun 2025 12:24:52 GMT

I have initialized a SnapMirror XDP relationship (Ontap 9.3P11 at DEST, 9.1P16 at SOURCE) and broken the relationship in order to copy (robocopy) ALL data from the LUNs within the volume to a new NAS volume for CIFS - so I'm migrating from LUNs to CIFS here.

The copy process is about to complete so I intend to resync the mirror, update, break and run robocopy to sync to copy.

Is this is valid procedure or am I missing somehting critical here?

Additional info:

There are 7 LUNs in the volume which provide 11 VMDKs to a single Windows Server that are spanned as a single 100TB disk. So I am emptying that bad design into a NAS CIFS share via a FlexGroup volume for future growth.

Re: SnapMirror Resync Procedure

TMACMD — Fri, 05 Jul 2019 15:03:03 GMT

Are you copying from the Source or Destination LUNS?

Why break the mirror? If you are copying from the DEST this would make sense as windows has a cow with a R/O LUN

If you are copying from the source, just resync it and leave it alone.

Use robocopy to update/sync as needed.

(FYI, a great tool called XCP located at xcp.netapp.com would also have worked!)

Re: SnapMirror Resync Procedure

nicholsongc — Fri, 05 Jul 2019 15:07:53 GMT

Tmac! We crossed paths at SBS years ago. Yes.. broke the mirror and copying from DEST.