Forum Discussion

Kisad's avatar
Kisad
Level 5
15 years ago

Difference between Suspended and Frozen Media

Hi

Can anyone please clarify on the difference Difference between Suspended and Frozen Media in Netbackup? I went  through the below link but wasnt clear.
Also was is a Frozen Image?

http://www.symantec.com/connect/forums/what-frozen-tape-really
7.1.x and Earlier
Backup and Recovery
Basics
NetBackup
  • J_H_Is_gone's avatar
    J_H_Is_gone
    15 years ago
    Frozen - Netbackup application will freeze a tape if it has a problem with it, or you can freeze it manually.  A frozen tape will not be use for any more backups.  A frozen tape - when it reaches its expiration date will not show it.  The images on the tape may still expire, but if you look at the GUI or command line the tape will still show its assigned date and other info.  Once the tape is unfrozen, if all the images on the tape have expired, the tape will go to scratch.  But if NetBackup froze the tape you want to see if you can find out why, as it may be bad and needs to be removed from the rotation.

    Suspended - Netbackup application will NOT auto suspend a tape.  You have to suspend the tape yourself.  (this makes it easier to tell if NB had an issue with the tape - frozen- or if you wanted to save the tape).  Once suspended the tape will not be used for any more backups.
    The big difference here is that once all the images on the tape are expired, the tape will go unassigned and go back to scratch, avail to be overwritten by the next backup.  Suspend can help you with putting a tape in a library to do restores from, preventing it from being appended to.  But at the same time allows it to expired in a normal manner.
  • Andy_Welburn's avatar
    Andy_Welburn
    Level 6
    15 years ago
    as they both prevent data being written to the media:

    media would be FROZEN as a result of media errors (read/write) greater than the allowable threshold for errors. This would prevent possible data loss by writing to a tape that is potentially faulty.

    media would be SUSPENDED (either by the user or automatically) usually temporarily to prevent said media from being written to (or possibly overwritten if they contain expired images that are to be imported, say).
  • Nicolai's avatar
    Nicolai
    Moderator
    15 years ago


    Frozen - no further writes to the tape - ever.

    Suspended - No writes to the until all images on the tape is expired (tapes become scratch). Then writes are resumed. This option is good if there is a structural problem with the tape e.g. a missing EOF/EOD marker (end of file, end of data).
  • J_H_Is_gone's avatar
    J_H_Is_gone
    Level 6
    15 years ago
    Frozen - Netbackup application will freeze a tape if it has a problem with it, or you can freeze it manually.  A frozen tape will not be use for any more backups.  A frozen tape - when it reaches its expiration date will not show it.  The images on the tape may still expire, but if you look at the GUI or command line the tape will still show its assigned date and other info.  Once the tape is unfrozen, if all the images on the tape have expired, the tape will go to scratch.  But if NetBackup froze the tape you want to see if you can find out why, as it may be bad and needs to be removed from the rotation.

    Suspended - Netbackup application will NOT auto suspend a tape.  You have to suspend the tape yourself.  (this makes it easier to tell if NB had an issue with the tape - frozen- or if you wanted to save the tape).  Once suspended the tape will not be used for any more backups.
    The big difference here is that once all the images on the tape are expired, the tape will go unassigned and go back to scratch, avail to be overwritten by the next backup.  Suspend can help you with putting a tape in a library to do restores from, preventing it from being appended to.  But at the same time allows it to expired in a normal manner.
  • J_H_Is_gone's avatar
    J_H_Is_gone
    Level 6
    15 years ago
    You said they tape could be suspend by the user or automatically....

    Under what conditions would NB suspend a tape automatically?
    (could be by some option I am not using?)
  • RollTheBones's avatar
    RollTheBones
    Level 4
    15 years ago

    "Suspended - Netbackup application will NOT auto suspend a tape.  You have to suspend the tape yourself.  (this makes it easier to tell if NB had an issue with the tape - frozen- or if you wanted to save the tape).  Once suspended the tape will not be used for any more backups."

    Not to sure about this but won't Vault suspend tapes when they are sent offsite?

  • J_H_Is_gone's avatar
    J_H_Is_gone
    Level 6
    15 years ago
    That might be my answer to my question to Andy,  I don't use vault, so I have never see NB auto suspend a tape.

    If vault will do that then I stand corrected on that point.
  • Andy_Welburn's avatar
    Andy_Welburn
    Level 6
    15 years ago
    I did read it before posting. I'll try & find it again (probably Monday now) & let you know.
  • Marianne's avatar
    Marianne
    Level 6
    15 years ago

    Ejecting tapes via Vault option suspends the tapes automatically.

    Extract from Vault Admin Guide:

    Use the Profile dialog box Eject tab to specify the:
    ■ Volume pools from which to eject media.
    ■ Suspend option. By default, Vault suspends media when it is ejected.....
  • Andy_Welburn's avatar
    Andy_Welburn
    Level 6
    15 years ago
    "...
    By default, NetBackup does not overwrite any of the formats on removable media, and logs an error if an overwrite attempt occurs......

    If media contains one of the protected formats and media overwrites are not permitted, NetBackup takes the following actions:
    ......
    ......
    ■ If the volume is in the NetBackup media catalog and has been previously selected for backups
      ■ Sets the volume’s state to SUSPENDED
      ■ Aborts the requested backup
      ■ Logs an error
    ......
    ..."

    ***EDIT***

    Came across this too in a T/N for EC96 - will have to try this out as I've never actually seen it happen:

    "...
    If the media physically expires, the tape will be suspended by NetBackup and will no longer be used for backups unless changed. Although it is important to note that the images are still intact and are not affected by this.
    ..."

    Unless its 'suspended' in spirit & not in name?!

    ***EDIT #2***
    This from a NB5.0 T/N (still valid?)
    "...
    If suspended tapes are observed and synthetic full backups are running, this is a normal occurrence. The tapes that were used for the original full backup get suspended while the backup is being performed. The media is returned to its normal state when the backup has been completed successfully.
    ..."