Tuesday, November 16, 2010

Creating a FlexClone volume in OnTap 7.3

Flexible volumes let users do some really kool things. One of my favorites involves cloning. We can take an existing FlexVol volume and create a clone from it, either using the volume itself (right now) or using an existing Snapshot copy from some point in the past (like before your server blew up). A FlexClone volume looks exactly like the volume it was created from (its parent FlexVol volume or another FlexClone volume), but it uses no additional physical storage!

This code shows you how easy it is to create a FlexClone volume by:

1) Cloning a flexible volume and
2) Splitting a FlexClone volume from the parent volume.

1) Clone a flexible volume

Display list of snapshots in vol1
FAS1> snap list vol1

Create a clone volume named newvol using the nightly.1 snapshot in vol1
FAS1> vol clone create newvol –b vol1 nightly.1

verify newvol was created
FAS1> vol status –v newvol

Look for snapshots listed as busy, vclone. These are shared with flexclones of vol1 and should not be deleted or the clone will grow to full size
FAS1> snap list vol1

Display space consumed by new and changed data in the flexclone volume.
FAS1> df –m newvol

2) Split a FlexClone volume from the parent volume.

Determine amount of space required to split newvol from its parent flexvol.
FAS1> vol clone split estimate newvol

Display space available in the aggregate containing the parent volume (vol1)
FAS1> df –A

Begin splitting newvol from its parent volume (vol1)
FAS1> vol clone split start newvol

Check the status of the splitting operation
FAS1> vol clone split status newvol

Halt split process. NOTE: All data copied to this point remains duplicated and snapshots of the FlexClone volume are deleted.
FAS1> vol clone split stop newvol

Verify newvol has been split from its parent volume
FAS1> vol clone status –v newvol

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