Veritas NetBackup™ Administrator's Guide, Volume II
- NetBackup licensing models and the nbdeployutil utility
- Additional configuration
- About dynamic host name and IP addressing
- About busy file processing on UNIX clients
- About the Shared Storage Option
- About configuring the Shared Storage Option in NetBackup
- Viewing SSO summary reports
- About the vm.conf configuration file
- Holds Management
- Menu user interfaces on UNIX
- About the tpconfig device configuration utility
- About the NetBackup Disk Configuration Utility
- Reference topics
- Host name rules
- About reading backup images with nbtar or tar32.exe
- Factors that affect backup time
- NetBackup notify scripts
- Media and device management best practices
- About TapeAlert
- About tape drive cleaning
- How NetBackup reserves drives
- About SCSI persistent reserve
- About the SPC-2 SCSI reserve process
- About checking for data loss
- About checking for tape and driver configuration errors
- How NetBackup selects media
- About Tape I/O commands on UNIX
About selecting media in robots
When NetBackup receives a request for a volume, it searches the EMM database for the media ID. The external media ID should correspond to the NetBackup media ID.
A request for a volume includes the following attributes:
The media ID
The device density
The file name that is used to link to the device that is assigned.
Table: How NetBackup selects a volume in a robot describes the order in which NetBackup selects a volume in a robot.
Table: How NetBackup selects a volume in a robot
Order | Description |
---|---|
1. | NetBackup searches the media catalog for a volume that is already mounted in a drive and meets the following criteria:
If a suitable volume is found, NetBackup uses it. |
2. | If NetBackup cannot find a mounted volume that satisfies all of the previous conditions, it checks the media catalog for any volume that is suitable.
|
3. | If a suitable volume does not exist or if a suitable volume is at end of media (EOM), NetBackup assigns a new volume. NetBackup may assign a new volume even if a volume is not full (because NetBackup received an EOM message from the drive). The new volume must meet all of the following criteria:
|
4. | If more than one volume qualifies, NetBackup chooses the volume that was least recently used. NetBackup then adds it to the media catalog and assigns it the specified retention level. |
5. | If there are no unassigned volumes of the requested type, the backup terminates with an error message that no media were available. NetBackuptakes no action. |