How to verify that the currently installed drivers will support the robotic library connected to the server

How to verify that the currently installed drivers will support the robotic library connected to the server

Article: 100013158
Last Published: 2018-04-03
Ratings: 0 1
Product(s): Backup Exec


When the device communicates properly with the operating system, it supplies an inquiry string to the operating system. In order for the device to work correctly with Backup Exec, the inquiry string that the device provides must match the inquiry string that is listed in the HCL.

Backup Exec will fail to recognize a robotic library and drivers will fail to load for the device if there is a mismatch between the device's Inquiry String and the Inquiry String Backup Exec is expecting for the device in the VSD load table.



If the library that is connected is not detected correctly, it will not either not show up in the Devices tab of Backup Exec or it will fail to respond to any commands.
If a bediag is run on the Backup Exec server, the following will show up in the device discovery portion of the ADAMM log section (Figure 1). The Inquiry string for the device is circled in red.

Figure 1

The Device Discovery shows "ERROR_INVALID_NAME" because the device identifier string "SONY LIB-162" is not contained in the Backup Exec look-up table for robotic libraries, the VSD Load Table. Backup Exec gets this data for the library name from the media server registry under HKEY_LOCAL_MACHINE on Local Machine\hardware\scsi\devicemap.

The devices connected are also displayed in the bediag in the Hardware Configuration Information section (Figure 2). The Inquiry String for the device is again circled in red.

Figure 2

The VSD Load Table is contained within the registry in the SCSICHANGER key located in HKEY_LOCAL_MACHINE on Local Machine\System\CurrentControlSet\Control. This table determines what virtual driver will be loaded to control the library connected to the media server. The VSD Load Table supporting this library will look like Figure 3.

Figure 3

Warning: Incorrect use of the Windows Registry Editor can have disastrous results on a server operating system. Great care should be taken when making changes to a Windows Registry. Registry modifications should only be carried out by persons experienced in the use of the Registry Editor application.

Note: For this library to be discovered in Backup Exec, the syntax of the identifier shown in the registry must exactly match what is in the VSDLoadtable.

Some libraries and tape drives can emulate different strings. Users can change the primary inquiry string to make it detect a different model than what is installed. However, changing the library string may change the behavior of the library.



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