Forum Discussion

Netbackup_Adm4's avatar
Netbackup_Adm4
Level 4
12 years ago

Maximize Tape Cartridge Usage

We recently installed LTO5 tape drives in our environment.  We have noticed since this change that many of our LTO5 tapes are going offsite with very little written to them.  This is causing us to go...
Backing Up
Backup and Recovery
Best Practice
NetBackup
  • Marianne's avatar
    Marianne
    12 years ago

    All of our backups are configured to create two copies. .... Copy 2 goes offsite.

    Can we assume that you are using Inline Tape Copy?
    And that you don't really have a problem with onsite media (as they can still be appended to on a daily basis) but with the tapes going offsite?

    If this is the case, it might be worth your while to run duplications afterwards - using something like Vault or SLPs. I know that with Vault you can limit the number of read drives and altreadhost. This will ensure more efficient use of media used for duplication.

    Depending on the amount of data to be duplicated, this may be time consuming, but you have to weigh up media savings vs the convenience of having all copies completed by the time the backup is done...

bills's avatar
bills
Level 5
12 years ago

Agreed - I've always used scratch pools and not worried about it.  At my last job we only sent tapes offsite when they were full - but there were a few cases when tapes would sit in the robot for months instead of going offsite.  In fact NetBackup tends to contribute to this by the way it selects tapes.  When faced with multiple choices in the robot, it will select the most recently written to.

In my previous experience, we had a pool whose jobs frequently spanned tapes.  So jobs would run, and leave partially full media - then more jobs would run the next cycle, would start on some of these tapes, span to new tapes (since NBU will choose empty tapes to continue spanned images if it can), then leave those tapes partially full.  The next cycle, it would choose the partial tapes from the 2nd cycle, since they were the most recently written to, effectively orphaning the tapes from the first cycle...

Bill