Over the past couple of days, I have been archiving published fMRI projects, and copying data from SD cards to start new ones. I have written previously about ways in which I have copied and verified copied files, and this is a quick update to that post to document another tool for verifying copies.

As far as the copying itself is concerned, I still swear by Teracopy. As far as verifying that copies have been successfully made though, I have recently started using Exactfile. The tagline “Making sure that what you hash is what you get” sums up the procedure for using Exactfile, once you have installed it on a Windows machine.

Exactfile in action
Exactfile in action
  1. Create a single file checksum, or, if you are comparing all the files and subfolders within folders (even massive folders containing gigabytes of fMRI data) a checksum digest (illustrated above). This will be saved as a file using which you can…
  2. Test your checksum digest. You locate your digest file and the copied data you wish to compare against the checksums, and it runs through making sure each file is identical.

That’s it – pretty straightforward. Step 1 takes a little longer than Step 2, and if you’re comparing hundreds of thousands of files, you should prepare to have this running in the background as you get on with other stuff.