Since Backup Exec 2010 R2 was released the ability to rotate USB disks holding Backup-to-Disk (B2D) devices has been provided. The correct way to configure the ability is to create a unique B2D device on each USB disk and then combine the B2D devices into a Device Pool so that regular jobs can then use the Device Pool to identify which (USB held) B2D device is online at the start of a backup job.
If the Backup Exec services are restarted with only one of the USB disks online, any B2D devices that were last active on the same drive letter that the currently online USB disk is using will be recreated on the online USB disk.
As an example:
If 4 B2D devices are created on 4 separate USB disks called
- USB-TEST1 (in I:\Test1-B2D, on USB disk 1)
- USB-TEST2 (in I:\TEST2-B2D, on USB disk 2)
- USB-TEST3 (in I:\TEST3-B2D, on USB disk 3)
- USB-TEST4 (In I:\TEST4-B2D, on USB disk 4)
Then the correct device status with just USB disk 4 online on the Media Server would be as per Figure 1 below:
Fig 1: USB B2D Devices before a service restart
Also the USB disk 4 will contain just the TEST4-B2D folder as per Figure 2 below:
Fig 2: Content of online USB disk before service restart
If the Backup Exec services are then restarted all four B2D devices will be online as per Figure 3 below:
Fig 3: USB B2D Devices after a service restart
This results in the online disk now containing folders for all 4 B2D devices as per Figure 4 below:
Fig 4: Content of online USB disk after service restart
Additionally if the online USB disk is then safely removed/ejected from the operating system, then Backup Exec only marks the B2D device that was correctly assigned to that USB disk as Offline, as per Figure 5 below:
Fig 5: Incorrect status of affected B2D devices after eject of USB disk.
On each USB disk create a file that has a name that exactly matches the folder name for the B2D devices of each of the other USB disks. This stops the process from incorrectly creating the folders on the wrong USB disk. As such the workaround for the example given in the description above, is to create 3 files called Test1-B2D, TEST2-B2D and TEST3-B2D as per Figure 6 below. Then create similar files on the other 3 USB disks.
NOTE: Make sure visibility of extensions is enabled as when you create the files for the workaround they have to be exactly as the folder name, hence no extensions.
Fig 6: Files required on USB disk to workaround the problem
Symantec Corporation has acknowledged that the above-mentioned issue is present in the current version(s) of the product(s) mentioned at the end of this article. Symantec Corporation is committed to product quality and satisfied customers.