How to delete "ghost" or "phantom" devices from the Windows Device Manager when using NetBackup

Problem

There are "ghost" or "phantom" devices from the Windows Device Manager when using NetBackup

Error Message

N/A: Symptoms such as drives going down, backups to tape not running, and more may be experienced.

Cause

Several things can contribute to the addition of ghost devices in the Windows Device Manager. Some of these include adding or removing hardware, changes to tape drives or tape libraries, failure to use persistent binding, static indexing, or hard ALPAs on storage area network (SAN) equipment. These sort of things allow changes to the SCSI device path presentation of a device to the operating system. These "ghost" devices can retain Port, SCSI, Target, and logical unit number (LUN) information that conflict with the active devices being used by Windows. Under these circumstances, hardware instability can result.

Running the device discovery wizard in NetBackup, for example, may list 20 tape drives when only 10 tape drives physically exist. This information is being pulled from the operating system and can incorrectly associate tape device information with the NetBackup hardware configuration. Also, when there are ghost devices, tape device drivers may "disappear" or roll back to the previous drivers after a tape device driver update.

Solution

To identify and remove the ghost devices from the Windows Device Manager on the problem media server(s), do the following:

1. Start the Command Prompt (cmd.exe) with Run as Administrator privileges.
2. From the Administrator: Command Prompt, run these two OS commands:
   set devmgr_show_nonpresent_devices=1
start devmgmt.msc
3. Then, select View from the drop down and select to Show Hidden Devices.
4. At this point, any ghost tape devices will be seen with lighter, transparent icon and can be removed. This is done by right-clicking the ghost tape device and selecting " Uninstall".
5. A reboot of the machine should be performed following this action.
6. It may also be necessary to delete and re-add any of these devices being used by NetBackup, as the current NetBackup configuration may have been pointing to one of these ghost devices, rather than the active one.
7. Prior to re-configuring any devices for use with NetBackup, ensure no additional ghost entries have been created following the reboot of the server. Repeat the procedure if needed, or consult Microsoft if the source of the entries cannot be found and they cannot be removed from the operating system.