This post was inspired by OnCommand Unified Manager and
an alert that came in about snapshot-reserve being over capacity on a SnapMirror
destination volume. In my noobishness at NetApp storage administration, there I
was scratching my head and thinking “do we have to break the SnapMirror and
apply the attribute to the DR volume, then resync?” Completely wrong! (In fact,
after breaking, attributes set on the DR volume would have been overwritten
once we did the resync…)
As an example, I have a cluster called na81 with two
Vservers - vs1 and vs2. There’s a volume called testshare on vs1 that’s being
replicated to testDR on vs2.
na81::>
snapmirror show
Source Destination Mirror
Relationship
Path Type
Path State Status Healthy
-------------
---- ------------ ------------- -------------- -------
na81://vs1/testshare
DP na81://vs2/testDR Snapmirrored Idle true
If I try to modify the % snapshot space (snapshot
reserve) on the DR volume I get this error:
na81::>
vol modify -vserver vs2 -volume testDR
-percent-snapshot-space 20
Error:
command failed: Unable to set volume attributes for volume "testDR"
on Vserver "vs2". Reason: Unable to set attribute
snapshot-reserve-percentage for volume. Reason: Operation not permitted on
read-only volume 'testDR'
So, what we do to change the % snapshot space on the DR
volume, is change it on the source and do a SnapMirror update. This is
demonstrated below:
na81::>
vol show -fields percent-snapshot-space
vserver
volume percent-snapshot-space
-------
------ ----------------------
vs1 testshare 5%
vs2 testDR 5%
na81::>
vol modify -vserver vs1 -volume
testshare -percent-snapshot-space 20
na81::>
vol show -fields percent-snapshot-space
vserver
volume percent-snapshot-space
-------
------ ----------------------
vs1 testshare 20%
vs2 testDR 5%
na81::>
snapmirror update -destination-path
na81://vs2/testDR
na81::>
vol show -fields percent-snapshot-space
vserver
volume percent-snapshot-space
-------
------ ----------------------
vs1 testshare 20%
vs2 testDR 20%
Simples!
And it gives me an excuse to post an image of a cute meerkat!
Image: Cute meerkat...
Thanks a lot :)
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