SnapLock ComplianceClock considerations with qtree SnapMirror

The ComplianceClock on a SnapLock qtree can be transferred with a qtree SnapMirror copy to either another SnapLock Compliance qtree or a SnapLock Enterprise qtree. However, the ComplianceClock might not be transferred to a non-SnapLock qtree.

After the qtree is copied, the ComplianceClock is stored on the destination qtree. At a qtree SnapMirror break, the qtree ComplianceClock is checked against the Data ONTAP ComplianceClock to ensure that the Data ONTAP ComplianceClock is not ahead of the qtree ComplianceClock. If the Data ONTAP ComplianceClock of the destination is ahead of the qtree ComplianceClock, the Data ONTAP ComplianceClock is drifted back to the qtree ComplianceClock.

Normally, the maximum amount of time the ComplianceClock can fall behind is bound by the length of the longest SnapLock qtree SnapMirror transfer to that system. However, there are two cases in which the amount of time that the ComplianceClock can fall behind is unbounded:

• When the source and destination SnapLock qtrees are on the same system.
• When there is a cycle of SnapLock qtree SnapMirror transfers across the storage systems. For example, there are SnapMirror transfers of one SnapLock qtree from storage system A to storage system B, and SnapMirror transfers of another SnapLock qtree from storage system B to storage system A.

You can work around these situations in the following ways:

• Change your SnapMirror configuration so that the source and destination SnapLock qtrees of every transfer are on different storage systems.
• Change the configurations so that SnapLock qtree SnapMirror operations are all going "one-way," such as always from storage system A to storage system B, and never from storage system B back to storage system A.