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Backup Exec 2012 not writing on additional tapes

Created: 04 Mar 2013 | 7 comments

Dear all,

i encounter the following issue:

Software: Backup Exec 2012 with all Hotfixes installed

Backup scenario: Backup to Tape (from Disk or directly from Server - doesn't matter)

Backup device : Quantum Autoloader 

Tapes: LTO4

The Tape Library is partitioned : [1-3], [4-8],[9-13], [14-16]

I have the follogwing Mediasets: Scratch, Tapes-Daily, Tapes-Weekly, Tapes Monthly


Tapes Daily -> Partition [1-3]

Tapes Weekly -> Partition [4-8]

Tapes Monthly -> Partition [9-13]

Scratch -> Partition [14-16]

Why Partitioning?

-> When backing up we experienced that if  a backup job has no free tape to write on it "steals" Tapes from different media sets -> so we partitioned the Tape Library and fixed this issue

Actual Issue:

[Example - this happened on several occasions already]

Just recently I did a monthly Backup on Saturday

So I put in 5 Monthly tapes in [9-13]

To make sure that everything works smoothly I fast-deleted all 5 tapes and put them in the "Tapes-Monthly" Media Set.

So far so good - all tapes were overwritable and the jobs i wanted to backup were alle correctly configured to use the right partition and Media Set.

Today I had a look at the backup and saw that only ONE tape had been written on and the rest was still "empty" - one job was on pause with the alert message to import/put in a new tape so backup can continue.

Well, according to the GUI everything SHOULD be working - tapes are overwritable etc... but ONLY when I change the tapes' Media Set back to "Temporary Media" and accept the alert message the next tape actually gets written on - otherwise it would have paused backup until christmas 2020.....

Can anyone tell me WHY this could happen?

 It annoys me to no end that this happens almost on a regular basis but is not reproducable on purpose..

I can't seem to find any clue as to why this is happening...

Thanks in advance for your advice/help!

Operating Systems:

Comments 7 CommentsJump to latest comment

VJware's picture

One should never manually associate tapes with media sets. If you do that, the tape inherits the overwrite/append protection before the backup starts.

sunnys's picture

Thank you for the answer.

I was fully aware that by changing the media set the overwrite/append periods will change.

Since this did not directly affect any of the tapes before the mentioned backup(all were empty and overwritable) I didn't mind it.

Is there anything else happening when changing the media set besides overwrite/append period?

Otherwise - sorry I seem to be missing your point here..?

Larry Fine's picture

If you manually associate an empty tape with a media set, BE will not be able to overwrite that tape until the overwrite protection expires on that "empty" tape.

Leave the tape in the "scratch" media set and let BE pull tapes from there as needed.

If you find this is a solution for the thread, please mark it as such.

pkh's picture

The root of your problem is that you have not set the OPP correctly.  If OPP is set correct, then the tape would be overwritable BEFORE the job starts and the job will happily overwrite the tape.  For example, if you have a weekly job and the OPP is set to 6 days, when the next weekly run starts, the tapes would be overwritable and your job will happily use the tapes.  There is no need to erase the tape or move it to scratch beforehand.   The following document should help

OPP and AP explanation

If you want to make your tape instantly overwritable, just associate them with the scratch media set.  There is no need to erase them.

sunnys's picture

Thank you both for your comments.

Sorry if I did not make myself clear.

I am quite familiar with OPP and know the impacts of resetting the media set concerning the OPP and append period.

The real Issue is the following:

The Tapes WERE overwritable before the backup started (and in the correct media set) - I double checked it before the backup started... (and besides the one that got data written on all other 4 tapes also were overwritable at the time I found out that backup was stalling). I very much would like to know why it did not work when according to the GUI it should have.

For the future I now know that using the Scratch media set to make sure it really works is one option.

But it does not really fix or explain my problem - I do not want to set every Tapes' media set back to "Scratch" at the start of the backup. It should work without problems (and it does in 70-85%) without my interaction - sometimes issues come up if i need to add a tape for example when the backup size is growing.

Short explanation and side-question as to why I deleted the tapes beforehand:

I inserted 5 tapes; 4 were full and 1 was half-filled with data.

All tapes were overwritable AND appendable ( yes they were and this is because i had to use a different media set apart from the regular one - the OPP and append period were a mismatch)

The Jobs were set to "append or if not possible, overwrite" (or similar sounding).

Side Question: 

If a tape is appendable AND overwritable and the Job is set to "append or if not possible, overwrite", in my logic it should append data to the half full tape and not overwrite it - is this correct?

This however was what I thought Backup Exec would do and therefore deleted the tapes (before I knew how to make use of the Scratch media set).

Please correct me if I'm wrong.


pkh's picture

Make sure that your ovewrite protection level is set to Partial or Full.  Click on the BE button ---> Configuration and Settings ---> Backup Exec Settings ---> Media Managemeent

On your question on append, your understanding is correct.  However there are some circumstances when a job will overwrite rather than append to a tape.  See my article on this topic, particularly th part on overlaping jobs.

Colin Weaver's picture

Putting the scratch tapes in their own partition and then targetting a diffrerent partition for the actual jobs will never use the scratch tapes so what is the point of Partition [14-16]?