Hyper-v backup

Hi,

We have BE 2010 R2 and we have an Hyper-v server on differnt server and we did install the hyper-v angent on this server, now we want to backup 6 virtual machiens on this hyper-v server, yesterday I did create a job to backup 6 server 2003 R2, In the morging I can see the job has been failed when try to restore the tape I can see that 4 of these machiens has been backed up but 2 server 2003 has failed. I can see that one serve 2003 that has 3 drives, from these 3 drive C, D get backedup but I can see that drive E got fully backedup  (I can see 80 gb and this the exact drive E space) but I see a read X on the drive E, and in the logs I cannot see why. why this drvie has this read X on it?

Thanks