Forum Discussion

Tabriz's avatar
Tabriz
Level 5
4 years ago

is considered full when the disk is full

Hi, there is LTO 6 tape  in netbackup .4.5 TB data writen to the tape.But media status show full? LTO 6 tape is 6.25 TB compressed. What can be reason? Thanks
  • Marianne's avatar
    Marianne
    4 years ago

    Tabriz 

    When a tape is full, NetBackup will not write anymore backups to it.
    NetBackup will look for a new tape to write backups.

    The Full tape will keep this status until ALL images (backups) on this tape have expired. The expiration date is determined by the Retention Period that is selected in the Policy Schedules.
    The tape will then be 'unassigned' and become available (go into Scratch).
    Only at this point can the tape be overwritten from the start.

Tabriz's avatar
Tabriz
Level 5

f the tape is full, does netbackup stop recording data or does it write new data and delete old data?

Marianne's avatar
Marianne
Level 6
4 years ago

Tabriz 

When a tape is full, NetBackup will not write anymore backups to it.
NetBackup will look for a new tape to write backups.

The Full tape will keep this status until ALL images (backups) on this tape have expired. The expiration date is determined by the Retention Period that is selected in the Policy Schedules.
The tape will then be 'unassigned' and become available (go into Scratch).
Only at this point can the tape be overwritten from the start.

  • Tabriz's avatar
    Tabriz
    Level 5
    4 years ago

    Marianne 

    Thanks for the response.

    • Nicolai's avatar
      Nicolai
      Moderator
      4 years ago

      Hello Tabriz 

      Netbackup don't know a tape capacity, it keeps writing until the tape drive sends the EOM (End of medium) signal to Netbackup, and then a tape exchange is initiated. 

      Another source to "lost capacity" is tape drive shoe shining, e.g not streaming the drive at it minimum rate. Every time a tape drive stop to wait for more data, a inter block gab is written to tape, add enough of them and you wont reach the tape capacity. 

      As mentioned, always count in native tape capacity, compression gain is considered a gift for the backup admin :-)

       

      • Tabriz's avatar
        Tabriz
        Level 5
        4 years ago

        Hello Nicolai 

        Thank you for the response.