Perhaps if a user is recovering a pen drive or external hdd, and there are no active threads/processes depending on it, it'd be possible to lock the drive?
This would mean that a user could happily continue using the computer, without possibly effecting the recovery process.
e.g. I've just finished recovering data from a user with an external hard drive. It took 6 hours. He spent the rest of the day, working through his emails, and doing work that is in his My Documents.
From a system admin point of view, it would be really useful to lock access to the partition/drive being recover