Snapmirror - can it be deleted
Posted on 2012-09-06
Dear Netapp and Storage experts.
I have a requirement to delete some snapshots from a Netapp filer including the first of two snapmirrors. This is where I stumbled upon, since I am wondering why there exist two snapmirror and what role resp. functionality they have.
Thus I have some questions:
1. How can there be two snapmirrors
2. Can the first snapmirror be deleted
3. What happens to once I deleted this snapmirror. Do I invalidate the second snapmirror and all snapshots above the first snapmirror as well?
4. Are Snapmirrors always indicators that the Snapshots are saved on Nearstores?
From my knowledge I compare these Snapmirrors to incremental RMAN backups.
The Snapmirror is the base (level 0) backup that contains all datafiles. All other Snapshots are what is known in RMAN as level 1 incremental backups. I Netapp terms they just point to the changed blocks within the snapmirror. Hence if I delete the lower snapmirror, all other snapshots above are invalidated and can be deleted as well.
If you could clarify my questions I'd appreciate it very much.
Here's an example of my snapshot list:
Aug 29 19:17 ORASID_02052012_SNAPSHOT_20121030
Aug 29 13:51 ORASID_02052012_SNAPSHOT_201221030
Aug 28 20:46 ORASID_30042012_SNAPSHOT_20121030
Aug 20 10:50 ORASID_30042012_SNAPSHOT_201221030
Aug 17 15:36 ORASID_27042012_SNAPSHOT_20121030 (Snapmirror)
Aug 17 11:53 ORASID_27042012_SNAPSHOT_201221030
Aug 16 17:25 ORASID_16042012_SNAPSHOT_20121030
Aug 16 13:46 ORASID_16042012_SNAPSHOT_201221030
Aug 15 17:40 ORASID_11042012_SNAPSHOT_20121030 <== Delete until here
Aug 15 12:52 ORASID_11042012_SNAPSHOT_201221030 (Snapmirror)
Aug 14 19:35 ORASID_30032012_SNAPSHOT_20121030
Aug 14 12:01 ORASID_30032012_SNAPSHOT_20121030
Aug 13 16:09 ORASID_29032012_SNAPSHOT_201221030 <== Start deletion