Come one, come all, to Part 6 of Deep Thought’s Leopard review! There is still a lot to cover in Leopard, but we hope to have our review completed within about a week, if all goes well. In case you’re just joining us, here’s what you’ve missed so far:

• Part 1: The Leopard UI
• Leopard screenshots
• Part 2: Spotlight and the Finder
• Part 3: Stacks
• Part 4: Spaces
• Part 5: iCal

In this section, we will discuss one of Leopard’s marquee features: Time Machine.

Before we start, a quick note about the score: the score at the bottom of the page only reflects the features discussed in this article. When all is said and done, we will give Leopard an overall score.

Insert “Back to the Future” reference here

Time Machine’s entire existence can be owed to one fact: very few people back up their files on a regular basis. Those who do, however, use an assortment of tools. Some use commercial software such as Retrospect. Some use the free basic backup software that came with their external hard drive. Some manually drag files onto a disk. Still others use software like Carbon Copy Cloner and SuperDuper!, which create exact copies of your hard drive on an external disk called clones (clones are nice because if anything goes wrong, you can start your computer off a clone of your internal hard drive).

Some of these backup procedures are easy, some are more tedious, but the bottom line is that millions of computer users do not regularly backup their data. Time Machine attempts to make backing up a Mac as simple as possible.

Time Machine is based upon two concepts: regular backups and file versioning; that is, Time Machine will keep multiple copies of a file so that you can revert to an earlier version of a file if you screwed something up. Windows Vista has similar features, such as Shadow Copy. In his Leopard vs. Vista video, Eric Dahl briefly touches on the differences between Shadow Copy and Time Machine.

So now that we’ve covered what Time Machine is, how well does it work?

Flux capacitor

Apple made activating Time Machine as simple as possible. All you need to do is hook up an external hard drive (Firewire or USB; it doesn’t matter). Mac OS X will then prompt you if you would like to use that drive as a Time Machine backup drive:

“Set it and forget it!”

One thing to note is that by default Time Machine will want a drive at least as large as the amount of data you have to back up (I would suggest something at least as large as your internal drive). You can use smaller drives, however, but you will have to exclude folders from the backup. I find that this works fine if you want to just back up your user account, for example. Because of how Time Machine is designed to work, you can only “opt out”; that is, you can specify what you do not want to back up, but you can’t just specify what you do want to back up. It’s the opposite of what you might normally expect, and seems a little unintuitive.

DO NOT WANT!

The first TIme Machine backup takes a long time, since it will back up just about everything on your drive (unless you tell it not to). A good idea is to run the initial backup overnight. You can still use your computer while Time Machine is backing up, but it does eat up a big chunk of system resources, so it may slow things down.

After Time Machine’s first backup, it will run the backup routine every hour. Hourly backups only save whatever changes have been made since the last backup, so it won’t constantly tie up your system. Time Machine remembers all backups for the last 24 hours, daily backups for the last month, and weekly backups until you run out of disk space on your backup drive (when that happens, Time Machine will ask you if it can delete older backups--I have yet to fill up my backup drive so I haven’t yet gotten to this point).

Maybe you’ve seen the infomercials where the guy from Ronco uses the catch phrase, “Set it and forget it!” That phrase describes Time Machine perfectly. Pick a backup drive and you’re done. By and large, from a user-friendliness standpoint, TIme Machine is excellent.

Aside from backup, Time Machine was designed to make it easier to recover files you may have accidentally deleted, like the time I inadvertently trashed my entire iPhoto Library and had to spend $100 on data recovery software. Um, I’d rather not discuss that. Recovering a file is pretty simple. In the Finder, navigate to the missing file’s location (for example, your Documents folder). Click the Time Machine Dock icon (or double-click the Time Machine icon in your Applications folder). You will then enter a funky, arguably over-the-top user interface made to resemble a starfield, with earlier versions of that folder’s contents extending back into space (screenshot). This interface is undeniably silly, but it works pretty well in reality.

If you recover an older version of a file but don’t want to overwrite a newer version, you can keep both.

To flip back to earlier versions, you can step back and forward using the arrow buttons, or you can pick a specific backup from the list along the right-hand side of the screen. Alternately, you can click one of the older version windows in the background. Once you see the file you want, select it, and click the “Restore” button. The file will be copied over from the backup and brought back to your current desktop. Easy. If you recover an older version of a file that you still have (say you want to have both the old version and new version), Time Machine will pop up an alert asking if you want to keep the copy on your hard drive ("Keep Original"), replace the copy on your hard drive with the older version, or if you want to keep both copies. This is a nice touch, and it’s a feature I would like to see used throughout the Finder.

If you don’t need the backups for a particular folder, you can delete them.

While in Time Machine, you can do a search or browse other folders, get info on a file, or use Quick Look. Additionally, if there’s a folder you don’t want to keep backups for, you can delete all the existing backups for a folder.

In terms of speed, TIme Machine is very fast at taking you through your backups. I haven’t really encountered any lags or pauses as Time Machine reads the backup drive.

Time Machine works with the Finder, Address Book, and iPhoto, as has been demonstrated numerous times. However, it will also work with Mail. TIme Machine does not work in iTunes, iCal, Font Book, or any other application so far as I can tell. The big question I have is whether or not Apple will allow developers to build compatibility with TIme Machine into their software. A quick search on Apple’s developer site yields this:

Introduced in Mac OS X v10.5, the Time Machine feature protects user data from accidental loss by automatically backing up data to a different hard drive. Included with this feature is a set of programmer-level functions that you can use to exclude unimportant files from the backup set. For example, you might use these functions to exclude your application’s cache files or any files that can be recreated easily. Excluding these types of files improves backup performance and reduces the amount of space required to back up the user’s system.

In other words, developers can make it so Time Machine doesn’t back up files you won’t need, but they can’t make their program take full advantage of Time Machine (for example, if you’re using a database application you can’t go back to an earlier version of the database without using the Finder).

Time Machine makes a great basic backup and recovery system for basic users, but some advanced users may find that it falls short. The biggest shortcoming? You can’t boot off of Time Machine’s backups. Also, as many have mentioned already, Time Machine is not well-suited for laptop users, since you need to have the external backup hard drive connected to the computer constantly for Time Machine to make its hourly backups. Apparently in pre-release versions, Time Machine would allow you to back up to hard drives connected to an Airport Extreme, but in the final version of Leopard, this feature is missing.

Lastly, hourly backups are great, but some things can slip through the cracks, since Time Machine does not make backups of files as changes are made. Here’s one very possible scenario:

1. Time Machine runs a backup at 1:45 PM.
2. You create an Excel spreadsheet at 1:50 PM.
3. You enter in some data and save it at 2:25 PM.
4. At 2:36 PM, you inadvertently delete it
5. Time Machine’s hourly backup runs at 2:45 PM.
6. Once you realize what happened, you open Time Machine
7. You realize that Time Machine didn’t save a backup to the Excel file since it was created then deleted between TIme Machine’s hourly backups.
8. You curse then go back and attempt to recreate the Excel file

I was a little disappointed when I found out that Time Machine didn’t create a new version of the file whenever it was saved. I don’t know the technical details that limits this capability (if any), but I would like to see Time Machine be able to do “live” backups in the future. Still, an hourly backup is better than no backup. It would have saved my bacon when I lost my iPhoto Library that time.

UPDATE 11 Nov 2007 10:53 PM PST: It appears it is possible to change the backup interval by editing a .plist file. I should read Mac OS X Hints more often!

Worth your while?

If you’re a typical home user, Time Machine is a great backup choice. It’s dead simple ad easy to use, and actually fun! Yeah, that’s right, a backup solution that’s actually fun to use; imagine that! Even if you don’t find yourself trashing important files that often, Time Machine is great, simply because you know it’s there in case you do delete something you need. If you’re a more advanced user,Time Machine may or may not satisfy your needs. My advice would be to give it a try if at all possible and see if it makes sense for your needs. Right now I have a dual-backup system set up. I use Time Machine for regular backups throughout the day, but I also keep a clone of my hard drive, and update it about once a week in case I have a complete meltdown and need to get back up and running in a pinch.

Time Machine is a great addition to Mac OS X despite its shortcomings. If you don’t backup your files regularly, you now have no excuse. Based on what it is (an easy backup and recovery tool), and who it’s intended for (mainstream consumers), I give Time Machine a solid 4.5 out of 5 overall.

Articles in this series

• Part 1: The Leopard UI
• Leopard screenshots
• Part 2: Spotlight and the Finder
• Part 3: Stacks
• Part 4: Spaces
• Part 5: iCal

Updated 11 Nov 2007 9:50 PM PST - clarified info on TIme Machine’s disk requirements.