Backing up only what changed with Burn by Zaweba

Once your first full backup is on disc, burning the whole lot again every month makes little sense. In Burn by Zaweba you can choose to burn only the files that are new or changed since the last backup, and the discs still restore as one complete backup.

That keeps repeat backups short and cheap in blank discs, without leaving gaps.

Running it after a first backup

The option comes into play after a first backup of a set. Run the full backup once, so every file has been burned and checked. From then on, when you run the same set again, choose Only files changed since the last backup. Burn then picks out the files that are new or have changed and burns just those.

For a photo library that grows by a few hundred pictures a month, or a documents folder where only a handful of files change, the difference is large. A backup that took several discs the first time may need only one afterwards.

How the discs stay connected

The clever part is the index. Every backup disc carries a restore index, and on the new discs that index points the unchanged files at the earlier discs where they already live. So the newest discs know about the whole backup, not only the files they hold themselves.

When you restore, Burn reads that index and asks for the right discs across backups. If a file was burned in the first backup and never changed, Burn asks for the disc it is on. If it changed last month, Burn asks for last month's disc. You don't have to keep track of which run holds which version.

Step by step

Open Burn and run the saved backup set from its chip on the home screen, or open the Backup Assistant and pick the set. Choose Only files changed since the last backup. Burn plans the discs for the changes, burns them, and checks every file against the fingerprint taken before burning, just as it does for a full backup.

When it finishes, label the new discs and store them with the earlier ones from the same set. The Backup log will show the run with its date, the discs used and the number of files.

Keeping a changes-only routine healthy

Keep every disc of the set. Because new discs point at old ones for unchanged files, the first full backup is still part of every later restore. Throwing it out to save space breaks the chain.

Store the set together, in order. Labels from Burn's Labels and covers tool make that easy, and the Backup log gives you the dates if you need to work out which discs came from which run.

Every so often, consider starting fresh with a new full backup. A long run of small change discs is perfectly restorable, but a fresh full backup gives you a tidy starting point and fewer discs to ask for. When you do, keep the old set until the new one has passed its check.

Leave the check after burning on. A change disc that fails its check should be burned again, just like any other backup disc.

Changes only alongside the other backup tools

Changes only is an option inside the Backup Assistant, so it works with everything the assistant already does. It uses the same backup set, spans several discs if the changes are large, and fingerprints every file. Restore from backup discs understands the links between runs, and the Backup log keeps the history. With Burn by Zaweba the first backup does the heavy lifting, and each one after it simply keeps up.