About Component-Based Backups

The components supported by the Oracle VSS writer are listed in Components Backed Up by the Oracle VSS Writer.

The name of the component is the value returned by an OnIdentify VSS message. The Selectable for Backup column indicates whether a component is eligible to be selected in VSS shadow copies.

Table 9-2 Components Backed Up by the Oracle VSS Writer

Component	Description	Selectable for Backup
Oracle Database	Contains the database files, control files, and server parameter file.	Yes
Control File	Contains the snapshot location of the control file for a database running in `ARCHIVELOG` mode, or the current control file locations when all database files are recovered to a consistent SCN. Note: The files included in the Control File component determine whether current control files or snapshot control files are excluded. For example, if the database is opened in read-only mode, then the snapshot control file location is excluded from the snapshot.	No
Server Parameter File	Contains the location of the server parameter file, if the instance is using one.	No
All TableSpaces	Includes all tablespaces in a snapshot.	No
tablespace_names	Selects individual TableSpaces.	No
Data file number=n	Selects individual data files. The metadata contains `RESETLOGS` information, tablespace number, tablespace name, and DBID.	No
ArchiveLogDest_n	Selects individual local archiving destinations other than the fast recovery area.	Yes
Fast Recovery Area	Includes all backup files and archived logs in the Fast Recovery Area in the VSS snapshot. Files backed up by VSS from the Fast Recovery Area can be subjected to deletion under space constraints.	Yes
Archived Logs	Logs in Fast Recovery Area	No
Backup Files	Backs up from Fast Recovery Area	No

You can select only Oracle Database, ArchiveLogDest_n, and Fast Recovery Area, exposed by the Oracle VSS writer during a backup. The availability of the components in Components Backed Up by the Oracle VSS Writer may depend on the database state. For example, if the database is in NOARCHIVELOG mode, then the Archived Logs component is not returned. Likewise, if the instance is not started with a server parameter file, then the Server Parameter File component is not returned.

Note:

The components that are not marked as Selectable for Backup are implicitly included by components marked as Selectable for Backup.

When you select Oracle Database component for backup or restore, all other components are implicitly selected for backup or restore. This implies that all files that are part of the selected component are candidates for backup or restore.

ArchiveLogDest_n and Fast Recovery Area components are defined to contain only log or incremental files. This means that the requester must backup files from these components only when creating a log for incremental or differential backup. Likewise, the requester must restore files from these components only when restoring from log or incremental or differential backups.

The files in all other components other than ArchiveLogDest_n and Fast Recovery Area define database files. This means that the requester must backup files from these components only when creating a full or copy backup. Likewise, the requester must restore files from these components only when restoring from full or copy backup.

Parent topic: About Backing Up a Database