Problem descr. short version:
Suspect corrupt vhd file, getting error 0x8007045D during backup to disk (DPM 2010) and while copying file manually on the host.
Problem descr. longer version:
I'm getting error 0x8007045D when accessing a vhd-file on our Hyper-V server. The server is a Proliant DL380G7, OS is Server 2008 R2 Ent. The guest server with the issues is the domain controller (SBS 2011) OS disk so it's critical to fix ASAP.
The problem occurred a couple of weeks ago. The DPM 2010 backup then started to fail every time the vhd was accessed (child partition snapshot). Error message in DPM 2010: "DPM encountered an error while performing an operation for \\?\GLOBALROOT\ Device....\..SBS2011-OS.vhd on ... The request cound not be performed because of an I/O error (0x8007045D)." I then tried to do a manual backup copy of the vhd to another drive, and I'm getting a simular error. While copying the vhd (after shutting down guest) I'm getting the error "Error 0x8007045D: The request could not be performed because of an I/O device error." I've tried this several times and ther error occurs at the same "spot" every time (with exactly 69.7 GB data left to copy).
The guest with SBS 2011 is running fine btw.
Tried running chkdsk on both host and inside guest, with no errors. Also tried to shut down guest, attach vhd in disk management and ran chkdsk, all good.
Don't know if this is important but the firmware on the disk controller was outdated when problem occurred, this is fixed now, just installed latest SPP (2013.09).
Not sure how to proceed, worried about destroying the SBS OS vhd since this is the domain controller (obviously) and the newest backup is about 2 weeks old. (Exchange database and user folders are on different disks btw so no worries there.).
Is it a good idea or is it risky to try expanding the vhd, and see if the Hyper-V manager expand job fixes the vhd file? (This is a fixed size vhd so shrinking it is not an option). Or is it worth a shot to try shutting down the guest, attach it on the host, create a new vhd, copy the data to new vhd? (have to consider security etc..:/)
Any ideas would be greatly appreciated.