drive index 0, Data error (cyclic redundancy check).

Hi,

I have a media server with 2 drives - A and B. All the while it was running fine until recently Drive A always encountered error  drive index 0, Data error (cyclic redundancy check). It was no problem when backup small to medium data, but when it backup huge data, it always starting to slow down around 1.3TB and drag until the end or failed with above error.

OS - Windows 2008 R2

Netbackup 7.5.0.4

Event log error - The device, \Device\Tape0, has a bad block or The device, \Device\Tape1, has a bad block.

Can you advice if this is the tape drive faulty or some other issue.

Thanks and regards,

Kwan