Differential backup?

[40oz]

I have a 12gb doom folder on my windows xp desktop that I want backed up on a 16gb thumb stick. I attempted to copy and paste the folder over, and the copying process said it would take an estimated 110 minutes, so I walked away and came back an hour later. When I came back I saw an error message saying the drive was full. I forgot to check if there was enough space on it and found afterwards that there was a folder full of old unimportant photos occupying a few gigs of space.

If I copy and paste my doom folder over again, it will take another two hours because windows XP is going to keep asking me if I want to replace all the existing files, which isn't necessary. Is there a command I can do that will compare the contents of the folders and only copy whatever didn't fit?

[chungy]

Windows Vista and later have robocopy (like rsync on Unix), and I think you can get it for Windows XP from MS's site, assuming they haven't trashed all the XP info yet. It'll mirror a directory like you want.

[hex11]

I used rsync on XP and older Windows before. You can get it with the rest of Cygwin stuff.

The downside is that it's got a bazillion options (the man page is huge) and you have to get the trailing slashes on directory paths exactly right (either include them, or omit them, depending on what you want the program to do...)

But once you figure out the basics, it's a really sweet program. And fast too! And you can ignore most of the stuff in the manual, just make sure you get those slashes right. ;-)

This is the simple script I use to backup my Amiga stuff to external HD:

#!/bin/sh -e
cd /mnt/g
rsync -vvr --size-only --del /mnt/g/amiga /mnt/bak |tee /tmp/rsync.log

So it's not complicated at all. Of course if you throw Cygwin into the mix, you have to understand how its paths translate to native Windows equivalents. That's probably the hardest thing if you never used it before... Practice on a small directory tree first.