I love Time Machine! I think it's one of the best additions to the modern Mac OS. However, sometimes Apple makes things too simple. While no one can argue the simplicity of just turning Time Machine on and letting it do its thing, sometimes I need a little more information than what the Time Machine System Perferences will show me. A couple of weeks ago I noticed that Time Machine was backing up as it normally does, but it seemed to be backing up several gigabytes of data (around 16GBs). I thought to myself that I hadn't made a bunch of changes or additions to my drive recently and I couldn't figure out what was being backed up? So I just let it go. Then I noticed two hours later that it was backing up roughly the same large amount of data. This is when I knew that something wasn't right. I'm well aware of the usual suspects such as a large Entourage database (I don't use Entourage anymore and don't even have it installed on this Mac). Also I know that if you're using a virtual machine such as Parallels or VMWare Fusiion, that the Windows image file is large and will cause this, but again I hadn't booted in Windows in a while and even if I did, I keep that image file on a external drive that wasn't connected at the time. I was clueless as to what was being backed up?
Back-in-Time 2 had the answers
While Apple doesn't disclose the actual files that are being backed up each hour, I found a neat little utility that does. It's called "Back-In-Time 2". It's designed to give you a better view of what Time Machine is doing and more importantly for me "which" files were backed up in any given hourly backup. The suspense was killing me! It takes the app a few minutes to report on what was backed up, especially if your Time Machine backup is happening over a network to a Mac OS X Server or Time Capsule. However, after waiting for several minutes I got my answer. For whatever reason several of the files in my Dropbox folder were being backed up every couple of hours. This also led me to give you this tip:
I love Dropbox too, but…
Dropbox.com is one of my favorite services. However, when I realized that the files in question were in my Dropbox folder I also thought about it for a minute and came to the realization that my entire Dropbox folder should be eliminated from Time Machine backups!
Anything in my Dropbox folder is already backed up to Dropbox.com as well as my other Macs that sync to Dropbox. This doesn't solve the mystery as to why certain files were appearing to Time Machine as being "changed" and therefore needing to be backed up every hour or so, but it does allow me to free up some space and time from my Time Machine backups.
Back-In-Time 2 helped me solve the mystery. It has several other nice Time Machine features as well. It's worth a look here.