How to restore data from an aggregate snapshot

What would you do if you found that your robocopy job had overwritten a folder, rather than appending new data to it? In a crazy panic you would probably run around looking for any tape or snapshot backup of the original data right?  But what if, unfortunately, there wasn’t any?

Now the only place left where you could recover the data would be aggregate level snapshots; so you look at aggregate snapshots and see it goes back to the time when you had data in place. Knowing that the data deleted from volume is still locked in aggregate’s snapshot, all of a sudden you feel thankful that you had some space reserved for aggregate level snapshot.

The next step is to recover the data, but now you have a new problem.  If you revert your aggregate by using “snap restore –A” then all the volumes in that aggregate will be reverted… which will be a much bigger problem. So, you have to take a different approach.  You use the aggregate copy function to copy the aggregate’s snapshot to an empty aggregate and then restore the data from there.

Here’s the how to:

		Pre-checks The volume you lost data from is a flexible volume Identify an aggregate which is empty so it can be used for destination (could be on another controller also) Make sure the destination aggregate is either equal or larger than source aggregate /etc/hosts.equiv has entry for the filer you want to copy data to and /etc/hosts has its IP address added, in case of copying on same controller loopback address (127.0.0.1) should be added in /etc/hosts file and local filername should be in hosts.equiv file Name of aggregate’s snapshot which you want to copy
	ExampleLet’s say the data lost volume was ‘vol1’, the aggregate which has this volume is ‘aggr_source’, the aggregate’s snapshot which has lost data is ‘hourly.1’ and empty aggregate where you will be storing data to is ‘aggr_destination’ Execution Restrict the destination aggregate using  ‘aggr restrict aggr_destination’ Start the aggregate data copy using ‘aggr copy start –s hourly.1 aggr_source aggr_destination’ Once the copy is completed online the aggregate using ‘aggr online aggr_destination’ If you have done copy on same controller, system will rename the volume ‘vol1’ of ‘aggr_destination’ to ‘vol1(1)’ Now export the volume or lun and you have your all lost data available.

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