If transaction logging is enabled, an IDB backup removes old transaction logs and starts creating new ones, which are necessary for an IDB recovery.
During restore
When configuring a restore, Data Protector performs a set of queries in the CDB and DCBF parts to enable users to browse virtual filesystems of backed up data. These browse queries are done in two steps. The first step is to select a specific object (filesystem or logical drive). If this object has many backup versions and/or copies stored, this can take some time because Data Protector scans the DCBF to build a lookup cache for later browsing. The second step is browsing the directories.
After specific versions of files are selected, Data Protector determines the required media and locates media position records that are used by the selected files. These media are then read by Media Agents and data is sent to the Disk Agents that restore the selected files.
During object copying or object consolidation
During an object copy or object consolidation session, the same processes run as during a backup and a restore session. Basically, data is read from source media as if it was restored and written to target media as if it was backed up. An object copy or object consolidation session has the same effect on the IDB operation as backup and restore. For details, see “During backup” on page 194 and “During restore” on page 195.
Exporting media
When a medium is exported, the following is removed:
•All the media position records from that medium are removed from the CDB.
•All objects and object copies that now have no positions on any other media are removed from the CDB part.
•Obsolete sessions (whose media have either been overwritten or exported) older than 30 days are removed (this can be modified using the KeepSession variable from the global option file). Session messages of such sessions are also removed.
•The medium record is removed from the MMDB part, and the DC binary file for that medium is removed from the DCBF.
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