Dedupe and tape backup job at the same time.

Hi all.

We normaly use a set of two LTO 6 tapes to do our weekly backup.

While I was running a dedupe test job I was also running our weekly tape job.

Problem is that the tapes suddenly started to fill up with the shadow copy Snapshot  to the size of 11+ Tb per tape.

Is this normal?

I tried to inspect the backup set, however it would report that the tape is empty.

Only after I canceled all the jobs that I was able to catalog the tapes and view the content.

Regards