Tape inventory fails with "Unknown MTF writer" error. Standalone drive is shown as empty and tape media is inaccessible.
MTF header on problem tape was written by a third-party application. To ensure that possibly valuable data on that media won’t be overwritten automatically, Veeam returns "Unknown MTF writer" error message after inventory of such tapes.
In case of tape library, the tape will be placed to “Unrecognized” media pool and it is not necessary to apply the fix.
In case of standalone devices, the tape becomes inaccessible.
This is resolved in Update 2b for Veeam Backup & Replication v8. Please install the latest update, (http://www.veeam.com/updates.html).
Post Update 2b Behavior Note:
After applying the update, inventory of a tape with MTF header written by third-party application will still fail. This is implemented to ensure that possibly valuable data on that tape won’t be overwritten automatically. However, the tape will be accessible in “Unrecognized” media pool and it will be possible to erase it manually.