Unable to delete a deduplication device from a CASO environment


A popup of "Unable to delete the deduplication disk storage" may be displayed when deleting a deduplication device from a CASO (Central Admin Server Option) environment. This can occur when a stand-alone server is changed to a Central Administration Server or a Managed Backup Exec Server.

The deduplication device cannot be imported or created if the error occurred once.

Error Message

Unable to delete the deduplication disk storage


This issue is caused because invalid device records are created while joining CASO.



A hotfix is now available for this issue in the current version(s) of the product(s) mentioned in this article. Refer to the Hotfix link under Related Documents at the end of this article to obtain the hotfix needed to resolve the issue.


Backup Exec 2012 Rev 1798 Service Pack 3 (TECH205351).


SP3 fixed the issue which is caused when a BE server joined CASO. If a BE server has joined CASO before applying SP3, the following workaround is required.



1) open command prompt on Central Administration Server

2) start osql command as follows

C:\> osql -d BEDB -S localhost\BKUPEXEC -E

3) type the following SQL script into the osql

DECLARE @deletedeviceid AS INT
SET @deletedeviceid = (SELECT DISTINCT MachineID FROM MachineDevice WHERE ScsiPort=255)
DELETE MachineDevice WHERE ScsiPort=255
DELETE Device WHERE DeviceID=@deletedeviceid


Applies To

Deduplication Option

Central Admin Server Option

Terms of use for this information are found in Legal Notices.



Did this article answer your question or resolve your issue?


Did this article save you the trouble of contacting technical support?


How can we make this article more helpful?

Email Address (Optional)