NetWorker: 'Write Protected' errors returned when writing to tape volumes

• Unable to label or relabel tapes
• Unable to write to appendable tapes
• Error: '\\.\Tape0: label write, The media is write protected. (Win32 error 0x13)'
• win_t_writer utility also fails with: 'Error Writing \\.\\\.\0 Error: 19'
• net helpmsg 19 to interpret the prior error confirms the Operating System return: 'The media is write protected.'

Errors of this kind are returned from below the application layer and cannot be overcome or resolved using software.

Known causes are:

• Physical write protect tab switched on tape
• Incorrect drivers or firmware for device or HBA
• Malfunctioning or misconfigured Encryption enabled at Library level
• Contention from other processes locally or on other zoned hosts

Because there are several known causes, there are different methods to resolve this issue:

Physical write protect tab.
Visually inspect the tape cartridges to ensure these have not been inadvertently switched on; this is their intended function, and prevents media writes of any kind.

Drivers and firmware for device and HBA
This applies generically and specifically; generically, consult your device and HBA vendor to ensure that your firmware and drivers are optimal for your system.
The inquire utility can reveal the firmware level of the device; the EMCReports utilities can reveal HBA firmware, driver, and ideal versions as well. EMCReports can be collected using the NSRGET utility: NetWorker: How to Use the NSRGet NetWorker Data Collection Tool
HP provides special drivers even for non-HP HBAs, which in once case proves to be the source of the write-protect error.

Library Encryption
Encryption functions should theoretically be transparent to applications and operating systems. However, another case has shown that accidentally enabling encryption can lead to errors. It is unclear whether this was due to misconfiguration or a malfunctioning encryption component of the library.

Contention
Because SANs are by their nature, intended to allow multiple host access, and hosts themselves may have multiple processes that attempt tape access, it is possible for other software to unexpectedly interfere and lock devices. This may include not only backup software but also host monitoring software which addresses tape devices.

Information about the win_t_writer and t_reader utilities can be found here: How to use the t_reader utility