How can I undelete files from an unRAID disk?
I recommend you to use the utility called diskinternals to recover deleted files, it is a really great thing which you will find interesting and useful to you. Good luck with it, I think you will find it helpful to you!
There are no known undelete tools for the Reiser file system, which the unRAID system uses for each data drive. However, there are techniques that can be used to recover files. See here for how to perform this on an unRAID array: http://lime-technology.com/forum/index.php?topic=5087.msg47070#msg47070 See this article and comments for some general help: http://antrix.net/journal/techtalk/reiserfs_data_recovery_howto.comments.