Recover after the loss of the source in a SnapMirror of SnapLock Compliance data

[cvanagt]

Hello

Consider a QSM between two SnapLock Compliance qtrees (resync allowed)

VOL1                             VOL1-MIR

SLC          -> SM        -> SLC

If the source is destroyed (DR), you can on the primary site :

- restore from an NDMP backup

- restore from a disk copy (SM or vol copy) made from the secondary volume

Can you incrementally reestablish the mirror from the newly restored source OR do you have to redo a baseline ???

Best regards,

Cyril

[BrendonHiggins]

My understanding is the QSM is based on a normal snapshot and once this relationship is lost you are into a new baseline.  This is because NDMP and QSM are about the files in the volume.  Snapmirror is all about the inodes which these higher level protocals know nothing about.

Hope it helps

Bren

[cvanagt]

Thank you Brendon

In fact, it is clear that a baseline is necessary if no common snapshot exist between source and destination :

After an NDMP restore -> no common snapshot -> baseline

But after a vol copy/VSM of the secondary backup volume, one should have a common snapshot (VSM or vol copy transfers active data AND all existing snapshots) and hence be able to resync between the two volumes, no ?

Cyril

[mwalters]

Hello Cyril,

If you have lost the source, replaced it with new storage, performed a QSM baseline from the destination, then at that stage you will be able to "switch" tidily in order to go back to the new storage becoming the source once more & the destination becoming the destination again.   That "switch" will not involve a baseline in any way.  Does that answer your question ?

Detail for this is in the "Archive & Compliance" documentation on the NOW site - for example, for ONTAP 7.3.2, see http://now.netapp.com/NOW/knowledge/docs/ontap/rel732/pdfs/ontap/archive.pdf

Hope this helps

Cheers

Mike

[cvanagt]

Thank you Mike and Bren for the confirmation.

After your emails and reading the doc, that's much clearer

Kind regards,

Cyril