Backup-to-Disk folders from offline USB disks are incorrectly created on an online USB disk during service restart.

Article:TECH155949  |  Created: 2011-03-18  |  Updated: 2013-05-28  |  Article URL http://www.symantec.com/docs/TECH155949
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Article Type
Technical Solution

Product(s)


Issue



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.

 


Solution



Workaround:

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.
 

This issue is currently under investigation by Symantec Corporation. Pending the outcome of the investigation, this issue may be resolved by way of a patch or hotfix in current or future revisions of the software. However, this particular issue is not currently scheduled for any release.  If you feel this issue has a direct business impact for you and your continued use of the product, please contact your Symantec Sales representative or the Symantec Sales group to discuss these concerns.  For information on how to contact Symantec Sales, please see  http://www.symantec.com Please be sure to refer back to this document periodically as any changes to the status of the issue will be reflected here.
 

Supplemental Materials

SourceETrack
Value2323321
Description

Service restart causes offline USB based B2D devices to be recreated on whatever USB disk is online.



Article URL http://www.symantec.com/docs/TECH155949


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