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 recovered. Most people are happy to not use the drive/pen whilst it is being recovered, or if they're too busy, just not have it recovered.
If a thread/process is sharing a drive/partition, it'd be really useful to have a list of which processes are preventing the drive from being locked, with a retry feature, that re-checks whether the drive can be locked, and if not re-generates the list, to show which processes are still using the drive.