How to Safely Transfer Data or Verify Backups (IntegrityChecker)
Suppose that you are switching to a new system, and you want to know that the data you have transferred is intact and 100% identical to the files you started with.
Data means image files, Lightroom catalogs, spreadsheets, mail, word processing files, videos, databases, etc—anything that you create and has value to you.
IntegrityChecker can take the worry out of this process. IntegrityChecker can verify any files on which it has been run before, even without the originals (there are alternatives such as “diffing” source and backup, but those are far slower, and require the original and the copy).
Some pro photographers burn DVD or BluRay discs containing files with IntegrityChecker support; these discs can be verified at any time. There are numerous such uses.
Step 1 — Update all files to be transfered
Run the IntegrityChecker update command on all files to be transferred, the files on your original Mac.
This essential step creates a hidden “.ic” file in every folder containing the critical SHA1 hash data for each file in that folder, so that when you copy or backup that folder, the hashes go along for the ride, allowing later verification. (Use the clean command to remove such files if you no longer want them).
Step 2 — Backup in preparation for transfer
Make at least two complete backups, then run the IntegrityChecker verify command on the backups, to verify they are intact (and readable). Verify is read-only, so it doesn’t matter whether the disc containing your files is a DVD or a hard drive or a USB thumb drive.
Step 3 — Copy and verify
Copy the data from your backup to the new machine, then run the IntegrityChecker verify command on the files now residing on the new machine, to verify they are intact (and readable). This same step can be applied to any backup you’ve made that has the IntegrityChecker .ic files in it.