About barcodes
When a robotic library has a barcode reader, it scans the media for barcodes and saves the results. The results associate the slot number and the barcode with the media in that slot. NetBackup obtains the barcode and slot information from the robotic library.
In the robots that have barcode readers, NetBackup verifies the barcode to ensure that the robot loads the correct volume.
If the barcode on the volume does not match the barcode in the EMM database, NetBackup does one of the following:
Assigns the request a pending status (for media-specific jobs such as a restore)
Uses another volume (for backup or duplicate jobs)
If a requested volume is not in a robot, a pending request message appears in the NetBackup Administration Console Device Monitor.
The operator must find the volume and do one of the following:
Check the Device Monitor to find a suitable drive and mount the requested volume in that drive.
Move the volume into the robot, update the volume configuration to reflect the correct location for the media, and resubmit the request.
If the volume is labeled, the automatic volume recognition daemon reads the label and the drive is assigned to the request. If the volume is unlabeled and not associated with a robot, the operator manually assigns the drive to the request.
NetBackup functions well whether or not barcodes are used. However, Veritas suggests using media with barcodes in the robots that can read barcodes.
Barcodes offer the following advantages:
Automatic media ID assignment
When you add new media to a robot, NetBackup is able to assign media IDs according to specified criteria.
More accurate tracking of volume location
A robot inventory update can determine which volumes are in a robot.
Increased performance
Not using barcodes can adversely affect performance for some robots. A robot that reads barcodes performs a scan each time it moves a tape. The robot stores the correct barcode in memory or verifies a previously saved barcode. However, if a tape does not have a barcode, the robot retries the scan multiple times, degrading performance.
Consider the following practices when you select barcodes for volumes:
Barcodes usually appear on the labels that are attached to the outside of tape volumes.
The maximum barcode length that NetBackup supports depends on the type of robot.
See the NetBackup Device Configuration Guide, available at the following URL:
Always follow the robotic library vendor's recommendations when purchasing barcode labels for use with NetBackup.
Ensure that the barcodes have the correct number of characters.
Barcodes can represent any combination of alpha and numeric characters, but different robots support different lengths of barcodes.
See the robot vendor's documentation to determine the requirements for a specific robot type.
Use barcodes without spaces (at the beginning, at the end, or between any characters).
Otherwise, the robot or NetBackup may not read them correctly.
Volumes in an API robot have a real or a logical barcode.
This volume identifier is used as the NetBackup media ID. This volume identifier is the volume serial number in ACS, TLH, and TLM robots.
For API robots, the barcode for a volume must be identical to the NetBackup media ID.
Match barcodes to media IDs by getting custom labels in the same series as the media IDs. For example, to match a set of media IDs from AA0000 to ZZ9999, get barcode labels in that series.
When a robotic library can contain more than one media type, assign specific characters in the barcode to different media types. Do so by using media ID generation rules.
Also, use barcodes to differentiate between data tapes and cleaning tapes or to differentiate between volume pools.