Troubleshooting Netbackup frozen media issues

When troubleshooting frozen media issues, it is important to understand the following:

  • Media must be unfrozen one at a time.
  • A media being frozen does not necessarily mean that the media in question is defective. Freezing media is a safety measure taken by the Netbackup application to help prevent further errors, drive damage, or possible data loss.
  • Investigate if there is any pattern to the media IDs, tape drives or media servers involved when media are frozen

What are frozen media?

Frozen media is the media that Netbackup does not use for backups. Netbackup stops directing the backups and the archives to frozen media. Netbackup never deletes a frozen media ID from the Netbackup media catalog, even after the retention period ends for all backups on the media. Netbackup does not unassign a frozen volume from the Netbackup volume pool when its backup images expire.

All unexpired backup images on frozen media continue to be available for restores.

Netbackup freezes the tape volumes for a variety of reasons, as follows:

  • If the same media id gets write errors three times within the time window, on more than 1 drive, it is assumed that the media is bad and Netbackup freezes the media.
  • If different media id's get the same error three times within the time window on the same drive, it is assumed the drive is bad and Netbackup places that drive into a "DOWN" state.
  • If the same drive gets errors three times within the time window with the same media id, then Netbackup assumes the media is bad and freezes it.

Logfiles?

The following logs are useful when troubleshooting frozen media:

  • Solaris & Linux
    • The bptm log from the media servers that froze the media: /usr/openv/netbackup/logs/bptm
    • The messages or syslog from the OS
    • The file /usr/openv/netbackup/db/media/errors on the media server
  • Windows
    • The bptm log from the media servers that froze the media: <Install_dir>\VERITAS\Netbackup\logs\bptm
    • The Windows Event Viewer System Log
    • The Windows Event Viewer Application Log
    • The log file <Install_dir>\VERITAS\Netbackup\db\media\errors

Note: Set bptm verbosity to 5. This is best practices when troubleshooting any media and drive related issues.

Status Codes

The following status codes can cause, or be a result of frozen media:

Status Code Error Message Reason
84 Media Write Error If the tape unit can not read or write to the tape correctly, this status code can occur when media are frozen
86 Media Position Error If the tape unit can not read or write to the tape correctly, this status code can occur when media are frozen
96 Unable to allocate mew media If media continue to become frozen, the backup job may end in a Status 96, because no more media available to mount.

Common issues

The following are five common situations in which media become frozen:

  1. The same media has excessive errors during backup
    FREEZING media id E00109, it has had at least 3 errors in the last 12 hour(s)
    Common causes and resolutions for this include:
    1. Dirty drives. Clean the drives that are freezing media. One of the first symptoms seen with a dirty drive is often frozen media. Drive cleaning should be done according to the manufacturer's suggestions.
    2. There may be an issue with the drive itself. Check the OS system logs mentioned above for any errors regarding tape devices or errors reported by the driver for the tape device. If any are found, follow the hardware manufacturer's recommendations for this type of error.
    3. There may be an issue with communication at the SCSI or Host Bus Adapter (HBA) level. Check the OS system logs mentioned above for any errors regarding SCSI or HBA devices or errors reported by their driver. If any are found, follow the hardware manufacturer's recommendations for this type of error.
    4. Ensure that the tape drives appear on the hardware compatibility list as supported for Netbackup. See related links below.
    5. Ensure that the media is supported for use with the tape drive by the tape drive vendor
  2. An unexpected media is found in the drive
    Incorrect media found in drive index 2, expected 300349, found 200244, FREEZING 30034
    This can occur under the following circumstances:
    1. If Netbackup requests a media ID to be mounted in a drive and the media ID physically recorded on the tape is different than that Netbackup media ID, media will freeze. This can happen if the robot needs to be inventoried, if barcodes have been physically changed on the media, or if the media was previously written to by another Netbackup installation with different barcode rules.
    2. The drives in the robot are not configured in order within Netbackup, or are configured with the wrong tape paths. Configuration of drives using the correct Robot Drive Number is important to the proper mounting and utilization of media. The Robot Drive Number, commonly set based on co-relation of the drive serial number with drive serial number information from the robotic library, should be determined and validated before the device configuration is considered complete.
  3. The media contain a non-Netbackup format
    FREEZING media id 000438, it contains MTF1-format data and cannot be used for backups
    FREEZING media id 000414, it contains tar-format data and cannot be used for backups
    FREEZING media id 000199, it contains ANSI-format data and cannot be used for backups 
    These are usually tapes written outside of Netbackup that have found their way into the library. By default, Netbackup will only write to a blank media or other Netbackup media. Other media types (DBR, TAR, CPIO, ANSI, MTF1 and recycled Backup Exec BE-MTF1 media) will be frozen as a safety measure. This behavior can be changed with the following procedure:
    1. From the Administration Console, proceed to Host Properties | Media Server
    2. Open the properties for the media server in question
    3. Select the Media tab
    The Allow Media Overwrite property overrides the Netbackup overwrite protection for specific media types. To disable overwrite protection, select one or more of the listed media formats Stop and restart the Netbackup services for the changes to take effect.

    Caution: Do not select a foreign media type for overwriting unless it is certain that this media type should be overwritten.

  4. Media was intentionally frozen
      It is possible to manually freeze media with the bpmedia command for a variety of administrative reasons. If frozen media is encountered and there is no record of a specific job freezing the media, media may have manually been frozen.
  5. Media is physically write protected
      If the media has a write protect switch that is set for write protection, this will prevent any writing to the media and Netbackup will freeze the volume.

Unfreezing frozen media

To unfreeze frozen media, use the bpmedia command. For example:

  • Solaris & Linux
    /usr/openv/netbackup/bin/admincmd/bpmedia \
       -unfreeze -m <mediaID> \
       -h <name of media server that froze media>
  • Windows
    <Install_path>\VERITAS\Netbackup\bin\admincmd\bpmedialist -m <mediaID>