The title should really be: “Restoring a SnapVault Relationship
in a DR Situation, where there was no relationship before.” That still probably
doesn’t make much sense, so here are some diagrams.
Image 1: 4-Copy
Data Protection
Image 2: 4-Copy
Data Protection Reversed after a DR situation
Using the lab constructed in this series; to simulate
losing site A, we break the SnapMirrors - 1 to 2 (from 2) and 3 to 4 (from 4)
in the diagram above - and then create the SnapVault (from 3 to 4) and make sure it’s
working as a vault, whilst acquiring an understanding of the Snapshots (on 2
and 4) that are in play.
Note 1: Highlighted
in yellow
are things I wanted to point out.
Note 2: Highlighted
in green are the action
commands that would be run in a DR situation.
Step 1: Break the
SnapMirrors
NCB1::>
snapshot show -vserver NCB1V1 -vol VOL5
Vserver Volume
Snapshot
--------
------- --------
NCB1V1 VOL5
60min.2014-10-14_1500
60min.2014-10-14_1600
60min.2014-10-14_1700
60min.2014-10-14_1800
snapmirror.0401c075-52ee-11e4-af9f-123478563412_2147484697.2014-10-14_184500
60min.2014-10-14_1900
snapmirror.0401c075-52ee-11e4-af9f-123478563412_2147484697.2014-10-14_190500
NCB1::>
snapmirror break
-destination-path NCB1V1:VOL5
NCB2::>
snapshot show -vserver NCB2V1 -vol VOL5
Vserver Volume
Snapshot
--------
------- --------
NCB2V1 VOL5
60min.2014-10-14_1500
60min.2014-10-14_1600
60min.2014-10-14_1700
60min.2014-10-14_1800
NCB2::>
snapmirror break
-destination-path NCB2V1:VOL5
Step 2: Apply
Snapshot Policy to the new Primary Volume (NCB1V1’s VOL5)
NCB1::>
volume show -vserver NCB1V1 -volume VOL5 -fields snapshot-policy
vserver
volume snapshot-policy
-------
------ ---------------
NCB1V1 VOL5 none
NCB1::>
volume modify -vserver NCB1V1
-volume VOL5 -snapshot-policy 10x10min_46x60min_2x24hrs
Warning:
You are changing the Snapshot policy on volume VOL5 to
10x10min_46x60min_2x24hrs. Any Snapshot
copies on this volume from the previous policy will not be deleted by this new Snapshot
policy. Do you want to continue? {y|n}: y
Note: Since the
previous policy was none, and the original source had the 10x10min_46x60min_2x24hrs
Snapshot Policy, I’m pretty sure (and think I’ve tested this already) that all
the historical Snapshot get managed correctly, and you can ignore the warning.
Step 3: Create the
SnapVault Relationship (after deleting the SnapMirror from NCA2V1:VOL5)
NCB2::>
snapmirror create -source-path NCB1V1:VOL5 -destination-path NCB2V1:VOL5 -type
XDP -schedule sv60min -policy 92x60min_16x24hrs
Error: command failed: Relationship with destination NCB2V1:VOL5
already exists.
NCB2::>
snapmirror show -destination-path NCB2V1:VOL5
Source Destination Mirror
Path Type
Path State
-----------
---- ------------ -------
NCA2V1:VOL5 DP NCB2V1:VOL5 Broken-off
NCB2::>
snapmirror delete
-destination-path NCB2V1:VOL5
NCB2::>
snapmirror create -source-path
NCB1V1:VOL5 -destination-path NCB2V1:VOL5 -type XDP -schedule sv60min -policy
92x60min_16x24hrs
NCB2::>
snapmirror show -destination-path NCB2V1:VOL5
Source Destination Mirror
Path Type
Path State
-----------
---- ------------ -------
NCB1V1:VOL5 XDP
NCB2V1:VOL5 Broken-off
Step 4: Resync the
SnapVault Relationship
NCB2::> snapmirror resync -destination-path NCB2V1:VOL5
Warning: All data newer than Snapshot copy 60min.2014-10-14_1800 on
volume NCB2V1:VOL5 will be deleted. Do you want to continue? {y|n}: y
NCB2::>
snapmirror show -destination-path NCB2V1:VOL5
Source Destination Mirror
Path Type
Path State
-----------
---- ------------ -------
NCB1V1:VOL5
XDP NCB2V1:VOL5 Snapmirrored
NCB2::>
snapshot show
Vserver Volume
Snapshot
--------
------- --------
NCB2V1 VOL5
60min.2014-10-14_1500
60min.2014-10-14_1600
60min.2014-10-14_1700
60min.2014-10-14_1800
60min.2014-10-14_1900
Note: Since the
_1900 snapshot has appeared we see the vault is already working!
Step 5: Create a
SnapVault-labelled Snapshot on the Primary Volume and test if it is Vaulted
NCB1::>
snapshot create -volume VOL5 -snapshot 60min.2014-10-14_1940 -snapmirror-label 60min -vserver
NCB1V1
NCB2::>
snapmirror update -destination-path NCB2V1:VOL5
NCB2::>
snapshot show -volume VOL5 -vserver NCB2V1
Vserver Volume
Snapshot
State Size Total% Used%
--------
------- ------------------------------- -------- -------- ------ -----
NCB2V1 VOL5
60min.2014-10-14_1500
60min.2014-10-14_1600
60min.2014-10-14_1700
60min.2014-10-14_1800
60min.2014-10-14_1900
60min.2014-10-14_1940
It’s double definitely working!
THE END
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