The ComplianceClock, which is implemented in software, can lag behind the system clock and must realign itself with the system clock periodically.
The ComplianceClock might lag behind the system clock in the following circumstances:
- The entire storage system is down (Data ONTAP
is not running).
- A volume is taken offline and then brought online again.
- A volume is taken offline and the system is rebooted.
- One of several SnapMirror configurations exist:
- The destination volume of the SnapMirror relationship is
removed from the SnapMirror schedule. However, the SnapMirror
relationship is not broken, and therefore the destination volume is not
brought online. The ComplianceClock can leap backward each time
the system is rebooted.
- The SnapMirror destination volume is updated relatively
infrequently (for example, monthly), and the system is rebooted well into
the period between SnapMirror updates.
Note: You can minimize the time by which the ComplianceClock lags behind the system clock by limiting the amount of time your system is down or your volumes are offline.
Some SnapMirror configurations might cause the ComplianceClock to lag behind the system clock. Breaking a volume SnapMirror relationship to a WORM volume can cause the ComplianceClock to lag behind the system clock contained in a volume SnapMirror destination. Therefore, you must perform a volume SnapMirror update operation before breaking the SnapMirror relationship.
The ComplianceClock is programmed to align with the system clock at a particular rate, thereby making up for small discrepancies automatically. The rate at which the ComplianceClock aligns with the system clock depends on the version of Data ONTAP your system is running:
- Before Data ONTAP 7.1, the rate is one day per year.
- For Data ONTAP 7.1 and later, the rate is seven days per year.
