Compatibility DLT 35/70 to 40/80

[Ayman Altounji]

I am assembling a disaster recovery server for an Microsoft SQL Server. This server is a Proliant 3000 with one internal DLT 40/80GB and Windows NT 4.0 SP6A, SQL Server 7.0 SP2 and Veritas Backup Exec 7.3 Rev 2575.
The Production Server is a Proliant 6400R with a library Compaq, with one drive DLT 35/70 and the same software.

The problem comes out when I restore a tape of the Production Server in the Disaster recovery Server. The SQL Server have 10 databases without considering the system ones (master, temp, etc.)
Some of the databases couldn?t be restored and the following happens:
The job starts in the usual way, it starts to read the tape and when it arrives approximately to 800KB it stays there for hours. The DLT led (tape in use) stays activated permanently.
The databases that couldn?t be restored don?t have anything in particular, and we have another ones that are bigger or smaller, and it could be restored
The versions of the DLT firmware are:
Production:

Compaq 35/70 GB DLT LIB Rev 4.04 Serial mn012281
Compaq 35/70 GB LDRV Rev 2150 (V80) Serial CX92054925

Disaster Recovery
Compaq 40/80 GB DLT DRV Rev 011A (V26) Serial CXA44P0142

I could do another tests, which succeeded:

1. Restoring the same tape from the Production Server (DTL 35/70) to the Development Server.
2. Doing the backup of the databases of the Supporting Server from itself, using the same back up software and the DLT 40/80
3. Restoring the tape resulting of the 2nd step in the Supporting Server.

I think the problem is not in the SQL Server, or in backup software. And it seems that the DLT 40/80 is not compatible at all with recorded tapes in DLT 35/70.

Any idea ??