CROSSCHECK

Syntax

Text description of the illustration crosscheck.gif

Purpose

To verify the existence of backups (backup sets or media-managed proxy copies) and copies (both archived logs and image copies) stored on disk or tape. The CROSSCHECK command only processes files created on the same device type as the channels running the crosscheck.

The CROSSCHECK command checks only objects marked AVAILABLE or EXPIRED by examining the files on disk for DISK channels or by querying the media manager for sbt channels. Table 2-2 describes the meaning of each status:

Table 2-2 Meaning of Crosscheck Status

Status	Description
EXPIRED	Object is not found either in file system (for DISK) or in the media manager (for sbt). For a backup set to be EXPIRED, all backup pieces in the set must be EXPIRED. Note: EXPIRED does not mean the same as OBSOLETE.
AVAILABLE	Object is available for use by RMAN. For a backup set to be AVAILABLE, all backup pieces in the set must have the status AVAILABLE.
UNAVAILABLE	Object is not available for use by RMAN. For a backup set to be UNAVAILABLE, all backup pieces in the set must have the status UNAVAILABLE.

The CROSSCHECK command does not delete any files that it is unable to find, but updates their repository records to EXPIRED. Then, you can run DELETE EXPIRED to remove the repository records for all expired files as well as any existing physical files whose records show the status EXPIRED.

If some backup pieces or copies were erroneously marked as EXPIRED, for example, because the media manager was misconfigured, then after ensuring that the files really do exist in the media manager, run the CROSSCHECK BACKUP command again to restore those files to AVAILABLE status.

Restrictions and Usage Notes

• The target instance must be started.
• A maintenance channel is not required when CROSSCHECK is used with a file that is on disk. If you use CROSSCHECK on nondisk files, and have objects created on device types that are not configured for automatic channels, then you must manually allocate maintenance channels for these objects. For example, if you created a backup on an sbt channel, but have only a DISK channel automatically configured, then you must manually allocate an sbt channel before the CROSSCHECK command can check the backup.

Keywords and Parameters

Syntax Element	Description
BACKUP	Crosschecks backup sets, backup pieces, and proxy copies that have status AVAILABLE or EXPIRED. Note that RMAN crosschecks all backups not marked UNAVAILABLE, even if they cannot be restored or if they are incremental backups whose parent full backup or copy no longer exists. By default, RMAN crosschecks backups of the whole database. See Also: "LIST Output". Use the KEY column of the output to obtain the primary key usable in the CHANGE and DELETE commands
COPY	Crosschecks datafile copies, control file copies, archived redo logs, and image copies of archived redo logs. By default, CROSSCHECK checks copies of all files in the database with status AVAILABLE or EXPIRED.
OF listObjList	Restricts the list of objects operated on to the object type specified in the listObjList clause. If you do not specify an object, CROSSCHECK defaults to all copies. See Also: "listObjList"
archivelogRecordSpecifier	Crosschecks the specified archived redo logs. See Also: "archivelogRecordSpecifier"
maintQualifier	Restricts the command based on the specified options. See Also: "maintQualifier"
recordSpec	Specifies the object whose availability status you are changing. See "recordSpec".
DEVICE TYPE deviceSpecifier	Allocates automatic channels for the specified device type only. This option is valid only if you have configured automatic channels and have not manually allocated channels. For example, if you configure automatic disk and tape channels and run CROSSCHECK ... DEVICE TYPE DISK, then RMAN allocates only disk channels. See Also: "deviceSpecifier"

Examples

Crosschecking All Backups and Copies: Example

The following example, which assumes that the default configured channel is DEVICE TYPE sbt, queries the status of all backups and copies on tape and disk. Because RMAN preconfigures a disk channel, you do not need to manually allocate a disk channel:

CROSSCHECK BACKUP;
CROSSCHECK COPY;

Crosschecking Within a Range of Dates: Example

The following example queries the media manager for the status of the backup sets in a given six month range. Note that RMAN uses the date format specified in the NLS_DATE_FORMAT parameter, which is 'DD-MON-YY' in this example:

# if you manually allocate an sbt channel, then RMAN does not crosscheck disk
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE sbt;
CROSSCHECK BACKUP 
  COMPLETED BETWEEN '01-JAN-01' AND '01-SEP-01';
RELEASE CHANNEL;

# to crosscheck only disk, specify CROSSCHECK DEVICE TYPE DISK
CROSSCHECK BACKUP DEVICE TYPE DISK 
  COMPLETED BETWEEN '01-JAN-01' AND '01-SEP-01';

# assuming that the default channel is sbt, you can crosscheck on both disk
# and sbt backups by simply running CROSSCHECK with the default channels
CROSSCHECK BACKUP COMPLETED BETWEEN '01-JAN-01' AND '01-SEP-01';