ONTAP Discussions

Volume snapmirror initial transfer

yaamibjammin
2,607 Views

When initializing a volume snapmirror, the source filer will create a baseline snapshot to transfer the data blocks to the destination filer volume.  Here's the question:  If the initial snapmirror has not yet completed but there are changes going on (additions, deletions, etc.) to the source volume, does the initial base line snapshot grow to capture those changes?  Or do these changes go into the snapmirror that occurs at the next scheduled snapmirror?

The reason I'm asking: I've seen a destination volume (same size as the source) get filled before the initial snapmirror is complete.  There is no dedup occuring on either volume.

Thanks!

2 REPLIES 2

andrc
2,607 Views

AFAIK only blocks in the baseline snapshot should be replicated during the initialisation and any changes replicated in subsequent transfers. Otherwise in theory the initial transfer could go on and on due to constant changes to the volume.

Can you give some more details of the situation where the destination volume filled up? I'm curious to hear what happened.

paulstringfellow
2,607 Views

As far as I know, no subsequent snapmirrors will occur before the baseline is done as SnapMirror is not actually “live” until that has completed..

Could be wrong but that’s how it’s always looked for me…

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