Could be a file in use error - FileIOFault to me sounds like a file is in use and is locked.
Generally when doing a P2V you should try to stop any services that would normally be doing work on a day to day basis.
Take a look through services.msc, identify any non-critical to Windows services, stop them, mark them as disabled, reboot, and then try the P2V process again. Don't forget to re-enable and start your services again once the P2V is complete! You could also try removing the shares temporarily if you suspect them to be causing the issue. (Take a look at open file sessions in your compmgmt.msc MMC to see if any files are being access remotely too).
This can also happen if the drive has dirty blocks on it:
A chkdsk run on that drive should resolve the problem.
If not like the previous user stated, make sure all application services are stopped for the P2V if you continue to have issues.