To protect against accidental or malicious loss or corruption of data, the storage management software provides a Snapshot feature that lets you make a logical copy of the content of a standard volume or a thin volume at a particular point in time. These point-in-time snapshots of volumes are referred to as " snapshot images." Taking a snapshot image is useful any time you need to roll back to a known good data set at a specific point in time. For example, you can create a snapshot image as a backup that you can use during a recovery operation.
When you take a snapshot image of a volume, the storage management software saves the read-only snapshot image in a repository associated with a snapshot group. To provide a host access to snapshot images stored within a snapshot group repository, you must create a snapshot volume.
- Base Volume
- Snapshot Group
- Snapshot Image
- Schedule and repository are associated with the snapshot group
Remember the following important details about the relationships between a snapshot image, a snapshot group, and a snapshot volume:
- A snapshot image is not host accessible. Only images in a snapshot volume are host-accessible.
- A snapshot group is a sequence of snapshot images of a single associated standard volume or thin volume. A volume used to create a snapshot image is referred to as a base volume.
- Each snapshot image is created in the context of exactly one snapshot group.
- A snapshot group uses a repository to save all data for the snapshot images contained in the group, though the repository does not contain the entire contents of a snapshot.
- All snapshot images within a snapshot group repository have a direct association with that snapshot group.
- A snapshot group has an association with a single volume.
- Each snapshot volume has a direct association with a snapshot image.
- Each snapshot volume has a persistent relationship to the base volume of the snapshot image for which the snapshot volume was initially created.
- The repository associated with snapshot volume has an association with a snapshot group.
For more information about the Snapshot feature, refer to the following topics:
- "Snapshot images" in the AMW online help
- "What is a snapshot group and why to I need it?" in the AMW online help
- "Why does a snapshot group need a repository?" in the AMW online help
- "Characteristics of snapshot groups" in the AMW online help
- "Creating a Schedule" in the AMW online help
- "Editing a Schedule" in the AMW online help
- "Starting a Rollback for a Snapshot Image" in the AMW online help
- "Stop snapshot volume" in the EMW online help
- "Stop snapshot image rollback" in the EMW online help