While using SnapMirror, you need to exercise adequate caution on several points, including the use of Snapshot copies, the use of SnapMirror commands, and the use of SnapMirror destination volumes.
- Do not delete Snapshot copies that SnapMirror creates in the source volume before copying the data to the destination. The most recent SnapMirror Snapshot copy is referred to as the newest common Snapshot copy (NCS). Incremental changes to the destination depend on the NCS. If SnapMirror cannot find the required Snapshot copy on the source, it cannot perform incremental changes to the destination.
- Do not use the snapmirror release or snapmirror break command on the destination volume or qtree unless you no longer need to copy incremental changes from the source. The destination must be actively functioning as a destination to receive incremental updates.
- Do not restrict or take the destination volume offline while SnapMirror is configured to transfer. Taking the destination offline prevents SnapMirror from performing updates to the destination.
- If Flash Cache is used in SnapMirror source and destination, during an application failover at the disaster recovery site, then there will be latency during the read operations on the destination as compared to the source, even though the destination system has the same Flash configuration as the source.
- If Flash Cache is deployed with synchronous SnapMirror, then there might be latency during the read operations on the destination storage system.