Incremental Solution


Today’s Question: FYI, there are backup applications that can do incremental backups on a block base. For large files, only changed parts (blocks on the disk) are backed up during incremental runs. For example: CrashPlan.

Tim’s Quick Answer: This isn’t a question, so much as a clarification. In yesterday’s edition of the Ask Tim Grey eNewsletter, I said (in the context of incremental backup) that “it isn’t possible to simply ‘update’ the parts of a file that have changed”. As noted above, my statement wasn’t accurate, as there are some software solutions that enable updating backed up files rather than backing up the same file a second time.

More Detail: The focus of my answer in yesterday’s email related to the benefits of a synchronization (or incremental) backup solution compared to creating an entirely new copy of your data (such as photos) for every backup operation.

As noted yesterday, I do highly recommend a synchronization backup solution compared to a more typical incremental backup solution. Both are incremental in the sense that they aren’t creating full copies of your files every time you backup. Instead, only the files that have changed are updated in the backup.

The key difference between what I refer to as an incremental backup versus a synchronization backup relates to what the backup copy of the data looks like. With software that I would place into the category of an “incremental” backup, the recovery process requires more time because the data must be restored in what can be thought of as an incremental process as well.

By contrast, software that I would fit into a category of a synchronization backup is making a backup that is an exact match of the “master” copy of the files. In other words, in the event of a hard drive failure if you have a synchronization backup you could essentially just replace your master hard drive with the backup hard drive and continue working (making an additional backup copy of your data first, of course).

Thank you, by the way, to the readers who pointed out my error in yesterday’s email. I love being able to help photographers find solutions to their challenges, and I appreciate it when readers catch an error and let me know, so I can pass the clarification on to readers.