Mount and Dismount Commands

The mount and dismount commands are relevant if you use automatic tape changers, such as jukeboxes or tape robots, for your Oracle database.

BRBACKUP or BRARCHIVE does the following:


       1.      Before accessing tapes for the first time, they perform the command defined in mount_cmdto automatically mount the tapes.

       2.      When the backup has finished, BRBACKUP or BRARCHIVE switches the corresponding tape devices to offline mode.

       3.      Then they call the command defined in dismount_cmd to automatically dismount the tapes.

For some tape devices, the tapes might not be switched to offline mode. The dismount command is then sufficient to dismount the tapes. In this case, do not set rewind_offline.

The mount and dismount commands used in most implementations require special control drivers, which are defined in the parameters tape_address_ctl or tape_address_ctl_arch.

Syntax of the commands mount and dismount commands:

mount_cmd = “<mount_cmd> <A> <B> <C> [<D>]

dismount_cmd = “<dismount_cmd> <A> <B> [<D>]

The command options <A> to <D> mean the following:

?      <A> identifies the database to be backed up and has the following structure:

<DBSID>-A   for BRARCHIVE and BRRESTORE with option -a|-a1|-a2

<DBSID>-B   for BRBACKUP and BRRESTORE without option -b|-b1|-b2

where <DBSID> is the Oracle system ID (that is, the database instance name)

This option can be used to identify a subset of tapes (“sub-pool”) for database backup. The additional extension -A and -B enables you to define and administer separate tape sub-pools for BRARCHIVE and BRBACKUP.

?      <B> identifies the tape devices, on which the mount or dismount operations are to be performed, using the control driver addresses:


where <dev_addr> is the driver address of the tape unit

One or more of the tape devices defined in the parameter tape_address_ctl can be addressed.

?      <C> defines the tape names to be mounted on the tape devices given in <B>:

<tape name1>[,<tape name2>,...]|SCRATCH

where <tape name> is the name of the tape to be mounted

The tape names are chosen from the backup volume list volume_backup (from BRBACKUP) or volume_archive (from BRARCHIVE) by the automatic tape administration. The assignment of the tapes on the tape devices can be defined freely by the mount command. The number of tape names can be greater than the number of driver addresses. In this case any tapes from this list can be mounted on the given tape devices.

The reserved tape name SCRATCH means that any unlocked tapes (that is, those for which the expiration period has finished) can be mounted. Which of the available tapes is mounted is decided by the mount command.

?      <D> transfers the name of a parameter file to the mount or dismount command, which contains additional configuration parameters for these commands. The name of the file is defined in the mount_par_fileparameter or by the command option -r|-parfile.

The user must provide the mount or dismount command in the form of a program, shell script or a batch file.

The successful completion of the command is indicated by the exit code 0 and the absence of any output (except for lines starting with #INFO).