Forum Discussion

MariusD's avatar
MariusD
Level 6
14 years ago

Full Multiplexed Tapes

Hi, I noticed  something in my backup enviroment. We have just LTO4 Tapes (800GB/1.6TB) for backup. Many tapes are with 430-480GB Full Multiplexed. How can be a LTO4 Tape with 430GB Full???  ...
7.1.x and Earlier
Backing Up
Backup and Recovery
NetBackup
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  • mph999's avatar
    mph999
    14 years ago

    NetBackup only marks a tape as full when it is 'told' to do so by the operating system, which is told by the tape driver, which in turn is told by the drive.

    If there is an issue, the most likely cause will be one of those.

     

    Kindest regards,

     

    Martin

shrisai's avatar
shrisai
Level 3
14 years ago

There may be software and hardware compression taking place.  This may be why you are seeing the difference in the amount of data on the tapes.  

Even though the tape only states that it has 430 gig of data on the tape it still could be full.  You can see this information when you run the "available media report".  It will show you if the tape is full and how much data is on the tape.  The amount can vary fairly significantly depending on what type of files your backing up.  

A backup of very large files will usually see a decent compression rate while a backup with many small files will not compress nearly as much.  Hope this helps!