Question

Free space on tape


Userlevel 2
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Likely a noob question, but just want to be sure things aren’t broken.

I’ve got a setup with Veeam B&R Community Edition on a single windows machine. I have full backups scheduled weekly, and daily backups every day, to a Quantum LTO-7 drive, using LTO-6 media.

The console reports the total capacity of the tapes as 2.1TB. Allowing for the whole base 10 / base 2 argument, this is what I’d expect. 

The full backup (done last night) reports total transferred is around 1.1TB, but the tape is only reporting around 250GB free. I’m expecting around a TB free (2.1TB - 1.1TB). 

You can also see that the “daily” tapes are reporting 2.1TB free (again, this is expected - there’s not a lot written, maybe ~90MB per day, so not enough to make a difference to the free space reported)

Is there something amiss somewhere, or am I going to have to migrate to LTO-7 media a lot sooner than I thought?

 

 


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Userlevel 7
Badge +7

Posting in the R and D forms might really help you. There are some smart Veeam employees that frequent the tape section and if you provide your case number they might give you some insight. 

Hey @Scott  → I’ve sent this thread to the tape PM; no need for duplicate posting.

Userlevel 7
Badge +4

Posting in the R and D forms might really help you. There are some smart Veeam employees that frequent the tape section and if you provide your case number they might give you some insight. 

Hey @Scott  → I’ve sent this thread to the tape PM; no need for duplicate posting.

My bad Rick. Didn’t see that. 

Hi guys!

The free space is reported by the drive based on End of Media attribute, so there is no mystery why B&R uses the set amount of storage. Simply because it was told by the tape > drive > library :)

  1. You may have additional partition created by any other software which ‘blocks’ full tape capacity. To deal with that you need to full erase the tape via vendor tools (i.e. reformat the tape)
  2. While the tape lifespan is decreasing the bad blocks are being recognized/noted by the drive and excluded from capacity. Could be the issue with either tape being old or drive being dirty. 
  3. Human error (I bet that’s not the case, but still): marketing capacity always doubles the actually tape free space due to the possible compression savings. B&R displays native capacity available on tape. Say for backup files compression takes no effect anyway as we compress data during backup to disk

Based on the description I’d go with cleaning / tape lifespan investigation.

Userlevel 7
Badge +7

All hail reply from @Dima P. 

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