How SnapMirror works

SnapMirror replicates data from a source volume or qtree to a partner destination volume or qtree, respectively, by using Snapshot copies. Before using SnapMirror to copy data, you need to establish a relationship between the source and the destination.

The SnapMirror feature performs the following operations:

1.	Creates a Snapshot copy of the data on the source volume.

2.	Copies it to the destination, which can be a read-only volume or qtree.

3.	Updates the destination to reflect incremental changes on the source, as per the schedule you specify.

The result of this process is an online, read-only volume or qtree that contains the same data as the source at the time of the most recent update.

Each of the following replication methods consists of a pair of operations, one operation each at the source storage system and the destination storage system:

•	Volume SnapMirror replication

•	Qtree SnapMirror replication

If a storage system is the source for one replication and the destination for another replication, it uses two replication operations. Similarly, if a storage system is the source as well as the destination for the same replication, it uses two replication operations.