The disk signature error "PartMgr" ID 58 may occur on its own or when a virtual machine backup is initiated.
You'll need to check whether there are disks that have the same disk signature.
In the case of Hyper-V, check if any of the VM disks inside the VM have the same disk signature as a host disk.
This error may occur as a result of a Disk2VHD P2V conversion.
The error usually shows up in the Event Viewer System logs:
Log Name: System Source: partmgr Event ID: 58 Task Category: None Level: Warning Description: The disk signature of disk X is equal to the disk signature of disk Y.
To view the disk signature, open the command prompt as administrator and:
The above command lists all disks, then
SELECT DISK N
N is the number of the disk you would like to acces
Now the disk signature will be displayed, such as 0805dae1
To change the disk signature:
UNIQUEID DISK ID=abcdef01
The disk signature wil then be updated to contain the byte value you entered.
More Info on BackupChain
BackupChain is a backup software for Windows and includes cloud backup and Windows Server 2012 backup amongst other modules that allow IT pros worldwide to protect their server farms.
BackupChain has also free virtual machine backup features included, such as live backup for VMs when creating a Hyper-V backup, VirtualBox backup, or VMware backup.
On the BackupChain website you will also find various freeware programs for Windows Server, including DriveMaker, a tool that you can use to map an FTP site to a drive letter.