Since upgrading from version 12.5 of Symantec Backup Exec, my virtual machine backup job had consistently failed. As highlighted by a colleague of mine, Backup Exec 2010 no longer utilises VMware Consolidated Backup (VCB) as it’s method of VM backup, but a new API called vStorage.
Due to this, the methodology of backing up virtual machines through vStorage is very different to that of VCB, and as such generated an error for each of my virtual machines during backup:
The virtual machine has a physical disk error (V-79-57344-38297), as shown in the above screenshot, was being reported for each virtual machine that has a Raw Device Mapping. In order to resolve this issue each Raw Device Mapping had to be changed from physical mode to virtual mode. The following actions were performed to achieve this:
1. Log into VMware vCenter as an administrative user.
2. Locate an affected virtual machine and safely power it down.
3. Right click on the virtual machine and select “Edit Settings”.
4. Locate the virtual hard disk drive that has been configured as a Raw Device Mapping.
5. Click remove and then when prompted select to delete the file. Please note this does not remove the data stored on your SAN LUN, this is simply a reference file used by the virtual machine itself.
6. Click OK, and wait for the Raw Device Mapping to be removed.
7. Right click on the virtual machine and select “Edit Settings”, select Add, and then select Hard Disk. Following the wizard, re-add your LUN or LUN’s and ensure that you set the compatibility mode to virtual and not physical.
8. Repeat for all affected virtual machines, and your all done!
For reference here’s VMware’s KB article on switching between RDM physical and virtual modes: http://kb.vmware.com/kb/1006599
