I ran into this error recently when attempting to back up a virtual machine in VMWare ESXi 4.1 using the Backup Exec Agent for VMWare. There are lots of articles out there for various causes of the VixDiskLib_Read error but none of them with the status of “Unknown Error”.
The problem was also very intermittent. Sometimes the virtual machine would back up fine and other times it would generate this error.
I jumped into VCenter and what I found [Read more…] about Unable to copy the virtual machine disk using the VMware VixDiskLib.