Administrator's Guide

How ADSM Stores Client Data

ADSM clients use ADSM to store data for any of the following purposes:

Backup

Copying files from client workstations to server storage to ensure against loss of data. Copies of multiple versions of a file can be stored.

Archiving

Copying files from client workstations to server storage for long-term storage. Copies are kept based on the retention time specified.

Space Management

Freeing up client storage space by copying a file from client workstations to server storage. This process is also called client hierarchical storage management (client HSM). On the client, ADSM replaces the original file with a stub file that points to the original in server storage.

The process of moving the client file to server storage is also called migration.

ADSM policy governs how the client data is stored and managed. Administrators define policy by defining policy domains, policy sets, management classes, and backup and archive copy groups. When you install ADSM, you have a policy that consists of a policy domain named STANDARD. The STANDARD policy domain contains a policy set, a management class, a backup copy group, and an archive copy group, all named STANDARD. For information about this default policy, see "Using the Standard Policy".

Figure 2 shows how policy is part of the ADSM process for storing client data. The steps in the process are as follows:

(1) An ADSM client initiates a backup, archive, or migration operation. The file involved in the operation is bound to a management class. The management class is either the default or one specified for the file in the client's include-exclude list.

(2) If the file is a candidate for backup, archive, or migration based on information in the management class, the client sends the file and file information to the server.

(3) The server checks the management class that is bound to the file to determine the storage destination, where to store the file within ADSM server storage. For backed-up and archived files, storage destinations are assigned in the backup and archive copy groups, which are within management classes. For space-managed files, storage destinations are assigned in the management class itself.

The storage destination is an ADSM storage pool, which can be a group of disk volumes, tape volumes, or optical volumes.

(4) The server stores the file in the ADSM storage pool identified as the storage destination.

ADSM saves information in the ADSM database about each file that it backs up, archives, or migrates. This information includes the file name, file size, file owner, management class, copy group, and location of the file in ADSM server storage.

If server storage is structured in a hierarchy, ADSM can later migrate the file to a different storage pool. For example, you may set up server storage so that ADSM migrates files from a disk storage pool to tape volumes in a tape storage pool.

Figure 2. How ADSM Controls Backup, Archive, and Migration

Files remain in server storage until they expire and expiration processing occurs, or until they are deleted. A file expires because of criteria set in policy or because the file is deleted from the client's file system.

For information on assigning storage destinations in copy groups and management classes, and binding management classes to client files, see Chapter 12. "Managing Client Data Using Policies".

For information on managing the database, see Chapter 16. "Managing the Database and Recovery Log".

For information about storage pools and storage pool volumes, see Chapter 9. "Managing Storage Pools" and Chapter 10. "Managing Storage Pool Volumes".