Backups to SVTL media hang in "Waiting for media" with "No media request" (87081)

A large majority of jobs targeting SVTL media remain in "waiting for media".
Diagnosing the Media Request gives a pop up window indicating "No media request".
In Media Management all SVTL tapes that should be full, show "99% used, 510KB space left".
As a result, any job that is assigned such tape (with 510KB free), will hang in "Waiting for media" with no media request.
The job is hung in a loop trying to write with no space, instead of trying other media.

Targeting blank SVTL media completes successfully.

SVTL media use the "../netvault/drives/willow/svdl.tpl" template containing the following values:
Media Reserve value = 1,048,576 bytes(1MB)
Media Discard Threshold = 10,485,760 bytes(10MB)
Device Segment Warning = 10,485,760 bytes(10MB)

Based on these configuration values, when a SVTL media has less than 10MB left it is automatically reported as full with no space left.
Therefore it would be impossible to fill an SVTL media and leave exactly 510KB free space unless there is some kind of corruption of the database.

When a device is initially added to the Device Manager, the template values are stored in the Device Tree files in the Database.
When the Device Manager starts up, the configuration options for it are loaded from the database and held in memory within the Device Configuration. The Device manager then accesses these in-memory values.
Previously to this incident the NetVault partition had been left with no space.
The DeviceTree files had been corrupted and the wrong information loaded in memory allowing full tapes to be used.

- Recreate the DeviceTree files as per SOL81366 http://supportpreview/Search/SolutionDetailPrintView.aspx?id=SOL81366
IMPORTANT:
Before recreating the DeviceTree files please understand this implies removing all you current devices and re-adding them.
So before proceeding it would be best to:
1- Keep a copy of the old DeviceTree files (as a fail safe)
2- Make note of all the devices and their exact names and configurations so you can reuse the same names and configurations when you add them again.

Finally, if you cannot afford downtime within your backup operation to implement the above an easy workaround is still available:
- Edit all Target Sets applied to your jobs to include:
"Specify minimum space required on media before backup = 50MB"
Note: You can use any values greater than the space seen left on the full SVTL tapes.