In playing the game of “What’s your favorite Leopard feature?”, Time Machine is always listed in the top five. The worst thing that I have to say to a client is, “I’m sorry, you’ve lost all of your data.” Unless that client happens have several hundreds of dollars to spend on data recovery, or a hidden backup drive under their bed, this is not good news. For many of us, our lives are kept in those little 0’s and 1’s and losing a hard drive could mean losing the pictures of your wedding, videos of your child’s first steps, that musical masterpiece you’ve been recording and tweaking for the past five years; it’s a BIG deal. Time Machine offers a seamless, intelligent backup solution built right in to the Mac OS. Now, if only my wish would come true and computers would start coming with external hard drives!

Now, with all backup solutions, Time Machine is not perfect. One of its features is that after the initial full backup, which could take a few hours, it creates incremental backups every hour of the information that was changed. As a consultant I especially love this feature because I’m often called to a client’s house when they’ve managed to delete a file that they really need. If Time Machine was on and working properly that file is usually just a few clicks away. I can literally “fly back in time” to before the customer deleted the file, and “restore” the file back on the computer. Pretty cool!

So, what’s the downside? Well, certain applications use databases for their files, so even if just part of that database is altered the entire thing is backed up every hour by Time Machine. One popular program that does just this is Entourage, Microsoft’s Mac version of Outlook. Entourage is a vital program for some businesses, especially those who run off an Exchange server. It houses mail, addresses, calendar items and to-do’s in one program. However, all of the data that Entourage uses is stored in a single database called an “identity.” These databases change slightly with each message sent or received, each new calendar appointment, each new address, etc. In other words, they change a lot! Time Machine sees this identity as a single file, so it continues to back it up every hour.

This week, I was called to a local business that runs it’s system off of an exchange server, so Entourage is the email client of choice for their design department. The problem was that many of the designers recently began receiving errors from Time Machine alerting them that their backup disk was full. The first designer that I helped had an Entourage identity that was 3.25GBs. This means that 3.25GBs were being backed up every hour. Yeah, that could fill up an external drive pretty fast. Luckily, there is a solution!

Time Machine allows one to choose to exclude certain files from its backup. To do this simply open up the Time Machine Preferences, found in System Preferences, select “Options” and hit the “+” button to add a new file to the exclusion list. If you’d like to exclude the Entourage database, it can be found in /Users/yourusername/Documents/Microsoft User Data/Office 2008 (or 2004, or X) Identities/Main Identity/database.

Unless you’re on an exchange server, which automatically keeps a copy of all of the Entourage information on it’s server, the obvious flaw with not having Time Machine back up your Entourage database is that you will now have to remember to do it yourself! To do that manually, you can easily drag the file from Finder to your backup volume periodically. Alternatively, you can use a third party backup program to incrementally back up that file for you to the external drive at an interval that you decide on. Personally, I’m a big fan of Carbon Copy Cloner, a free application that you can easily download from or, which can perform schedule tasks like backing up the Entourage database for you.

If you find your Time Machine backup disk is filling up quicker than you think it should, check to see if your programs use a database feature like this and hopefully excluding that file will be a solution for you. If it isn’t, remember there are always more backup solutions out there! The most important thing is that you back up regularly, however you choose to do it. Speaking of which, when was your last backup?


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