How snapshot images are used
A snapshot image is a logical, read-only copy of volume content, captured at a particular point in time. You can use snapshots to protect against data loss.
Snapshot images also are useful for test environments. By creating a virtual copy of data, you can test data using the snapshot without altering the actual volume itself. In addition, hosts do not have write access to snapshot images, so your snapshots are always a secure backup resource.
In this section...
The Snapshots feature uses copy-on-write technology to store snapshot images and use allocated reserved capacity.
When creating and using snapshots, review the following requirements and guidelines.
A base volume is the volume used as the source for a snapshot image. A base volume can be either a thick volume or a thin volume and can reside in either a pool or volume group.
Use schedules for collection of snapshot images, and use snapshot consistency groups to manage multiple base volumes.
You can create a snapshot volume and assign it to a host if you want to read or write snapshot data. The snapshot volume shares the same characteristics as the base volume (RAID level, I/O characteristics, and so on).
A rollback operation returns a base volume to a previous state, determined by the selected snapshot.
