I often have problems when I try to copy files on the computer; different problems depending upon the operating system I’m using. Maybe this happens to me more as a control/organization freak; I move things around a lot, and often back things up by copying them to a different drive.
A copy operation is really a sync. (Or is it “synch” – maybe that’s why noone’s gotten it right so far!) If I try to copy into a folder where things already exist, what I must be doing is syncronizing the folders – getting the latest files, etc. In fact there’s not nearly enough syncronization going on – many, many times when I do a backup all I’d really like to move is the changed files; but I end up having to delete all the source files and recopy all the files. rsync apparently does this well, but with several problems: i still don’t understand exactly how it works; it’s not smart when both files have been changed; it doesn’t work on Windows (big surprise, there’s probably one there but it must by definition suck if it’s Windows software) or have a GUI for OSX.
One of the biggest problems is interrupted copies. Any time a process might come up with messages – please check for and front-load (tell me before you start) those messages; or back-load them (wait till the process is done then tell me what went wrong and help me cure it. Disc full? Check before to be sure there’s enough space, then “reserve” that space till the operation is done. Files locked or bad permissions? Check first! Now, I’m sure there might be issues that happen after the copy has started – unexpected errors. Just save them and continue copying if you can. Sometimes OSX is in the middle of a copy, and it runs into a file that chokes it, and it just puts up a dialog box then stops! As I recall this was a lot worse in OS9. On the other hand, I’ve had “move” operations fail on Windows (moving files from one disc to another, a copy-then-delete-original) and the files would actually be gone! This is unacceptable.
Of course, true journalling file systems and the like will make this problem both better and worse; you may have old copies of files forever; but sometimes you want to move all the copies, and sometimes you might only want to move the most recent copy.