I've recently been given the task to migrate about 200GB of data from one dedicated server to another. As this will take a week or more, I've been taking a snapshot of the current files on the FTP server using wget's mirror feature. However, since other users will probably be uploading / changing stuff in the meantime, the snapshot that I have made will not include the most recent changes.

Since I only have access to FTP on this server, I'm planning to write a script that will recursively do a FTP stat on all files in the FTP folder, and compare the directory listing against the snapshot I have locally. If there are differences in the number of files, then I know files have been added or deleted. If the modification dates have been changed, then I know the files have been changed, and should redownload those files specifically.

Am I missing anything in my approach, or are there any possible improvements to this approach?