Vault tapes capacity

[Will_Restore]

Suddenly one site using more tapes for offsite vaulting.  Checking KB counts on "full" LTO4 media show just 500Gb on new tapes vs 800Gb or more with older tapes.  I was beginning to think we got a batch of bad tapes but find Full tapes from regular backups to new media are expected capacity where Vault tapes are not.  I know it's the hardware that signals when a tape is full so how come Vault tapes are filling up sooner?  Scratching my head on this one. 

[Dyneshia]

Was encryption or compression turned on via the policy ?

[Will_Restore]

Not permitted on Vault policy but I double-checked and none of the policies using encryption or compression.

[mph999]

Are particular drives used for vault copies perhaps, different firmware level ??? Just an idea ...

[Will_Restore]

Thanks, checked & all firmware at same level.  Same drives used for regular backups & vault copies.

[Will_Restore · Accepted solution]

Oh my!  Just checked library logs and it seems to think the new Sony tapes are LTO3. 

Very odd that regular backups capacity is fine and only vault copies are affected.