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.

You can specify a SnapMirror source and destination relationship between volumes or qtrees by using one of the following options:

•	The /etc/snapmirror.conf file

•	The snapmirror.access option

•	The /etc/snapmirror.allow file

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, 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 volume SnapMirror replication, qtree SnapMirror replication, or SnapVault replication consists of a pair of operations. There is one operation each at the source storage system and the destination storage system

Therefore, 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.