ALLOCATE CHANNEL FOR MAINTENANCE

Syntax

Text description of the illustration rcmsyn35.gif

Purpose

To manually allocate a channel in preparation for issuing a CHANGE, DELETE,or CROSSCHECK command. Note that if you use CONFIGURE to set up automatic channels, then RMAN can use these automatic channels for maintenance operations; you do not have to manually allocate them.

If RMAN allocates the an automatic maintenance channel, then it uses the same naming convention as any other automatically allocated channel. If you manually run ALLOCATE CHANNEL FOR MAINTENANCE, then RMAN uses the following convention for channel naming: ORA_MAINT_devicetype_n, where devicetype refers to DISK or sbt and n refers to the channel number. For example, RMAN uses these names for two manually allocated disk channels:

ORA_MAINT_DISK_1
ORA_MAINT_DISK_2

You can allocate multiple maintenance channels for a single job, but you should only use this feature in these scenarios:

• To allow crosschecking or deletion of all backup pieces or proxy copies, both on disk and tape, with a single command

• To make crosschecking and deleting work correctly in an Oracle Real Application Clusters configuration in which each backup piece or proxy copy exists only on one node

  See Also: Oracle9i Recovery Manager User's Guide to learn how to crosscheck and delete on multiple channels

Restrictions and Usage Notes

• Execute this command only at the RMAN prompt.

• The target instance must be started.

• Do not specify a channel ID.

• You cannot allocate a maintenance channel to a shared session.

• You cannot prefix ORA_ to a channel name. RMAN reserves channel names beginning with the ORA_ prefix for its own use.

Keywords and Parameters

DEVICE TYPE = deviceSpecifier	Specifies the type of storage device. See Also: "deviceSpecifier" Note: If you do not specify the DEVICE TYPE parameter, then you must specify the NAME parameter to identify a particular sequential I/O device. Query the V$BACKUP_DEVICE view for information about available device types and names.
allocOperandList	Specifies control options for the allocated channel. See Also: "allocOperandList"

Examples

Deleting a Backup Piece: Example

This example deletes a backup piece from the media management catalog:

ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE sbt;
DELETE BACKUPPIECE '/oracle/dbs/01aj3q5012';

Crosschecking a Backup Set: Example

This example crosschecks the backup set with primary key 828:

ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE DISK;
CROSSCHECK BACKUPSET 828;

Crosschecking on Multiple Nodes of an Oracle Real Application Clusters Configuration: Example

In this example, you perform a crosscheck of backups on two nodes of an Oracle Real Application Clusters configuration:

RUN
{
  SET AUTOLOCATE ON;
  ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE DISK CONNECT 'SYS/change_on_install@inst1';
  ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE DISK CONNECT 'SYS/change_on_install@inst2';
  CROSSCHECK BACKUP;
}

Deleting on Disk and sbt Channels with One Command: Example

In this example, you delete five backup sets from both disk and tape:

ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE DISK;
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE sbt;
DELETE BACKUPSET 1,2,3,4,5;