Wednesday, December 23, 2009

Time Machine is a good product. It has a great interface and it does an excellent job of protecting your system every hour. It also provides simple access to old versions of files and performance is not bad for single file recoveries. Even with my method in place I still use it to provide historical access to my file data. Time Machine however, is not really great at rapid full-system recoveries.

If you have a hard drive failure or corruption you’ll need to replace the drive, reinstall the OS and then use migration assistant to restore the data. You can also restore directly from a Time Machine backup but you first need to lay the base OS down. In either case this takes time, especially if you’re doing the recovery across a WiFi-connected Time Capsule. In the best case, you are looking at a few hours of staring at progress bars. Always a good time.

The alternative is to make an image backup to an externally connected hard disk using a utility like Shirt Pocket Software’s SuperDuper. The advantage of SuperDuper is that it has a smart update feature that, once the original image is created, only updates the changed files on subsequent backups, shortening them to a few minutes. This backup is bootable, meaning that you can still boot your Mac if your internal hard drive fails by pressing the option key and selecting this drive as it comes up. Depending on when you did your last SuperSuperDuperDuper backup you may have only lost a few files.

Remember, however, that the goal was zero data loss and despite SuperDuper’s smart update capability you’re probably not going to run it constantly. You could restore the changed files from your Time Machine backup but that still means you will have to find the files that were changed and restore them. That takes time. It also means that you may be out of sync by as much as an hour.

What changes on your Mac hourly? If you’re like me, most of your changes on an hour-by-hour basis are the files and documents you’re working on, typically found in the User directory. Applications and modifications to system settings, especially after you have been using your Mac for a while, tend to change far less frequently.

To capture these active files I use Dropbox, although .MAC should work too. Dropbox has an excellent Mac client and can be used for free up to 2GBs. 2GBs it turns out is a lot of data if all you’re storing is word processing, spreadsheets and the occasional powerpoint presentation. Every file saved is replicated to the Dropbox cloud. At Storage Switzerland we use this service for collaboration as well as storage, so we’ve paid for a 50GB license.

On a hard drive failure, I boot from my external Mac drive, which I update about once a week or whenever I have installed a new application. When this boot happens the Dropbox client then connects with the cloud services and resyncs this "out of date" Mac. Even in the worst case scenario, where the external backup hasn’t happened for a week, it only takes a few minutes to recover. More importantly, my Mac is back in operation and I can use it while it’s being updated.

The only data missing from this is email. Again if the SuperDuper backup is really a week out of date, then email does have to be downloaded again, which can up to five minutes or so. But again, it happens in the background and I can get back to work while this completes. Now, this does work best on an IMAP mail configuration and I’d recommend for your email.

Obviously, everything described so far will work on any Mac. The MacBookPro part of the solution comes from the fact that the current MacBooks can have their hard drive replaced in a matter of minutes easily. The external drive I have connected to my MacBook is a standard 2.5" hard drive mounted in an easily accessed case. This is the drive that the SuperDuper backups go to. If I have a failure, I can pull the drive out of this case and install it in the MacBook Pro in less than five minutes, turn the MacBook back on and let Dropbox resync the changes. In almost every case I suffer no practical data loss, except maybe for a few preference settings that I may have tweaked between SuperDuper backups.

Where does time machine fit in? It depends on how you want to use it. I see limited value in having months old copies of system settings and previous versions of applications. I do like the ability to go back in time and pull an old version of a file so I’ve set up Time Machine to backup just the User directories. That way music and pictures are captured since I don’t store those on Dropbox. It also means that my time machine backups can go much further back in time since space is not wasted on the other parts of the OS that I’m capturing on my SuperDuper backups. The choice is yours, some people will want the extra safety net of having Time Machine and feel they have the disk space to burn.

The only weakness is it doesn’t provide an off-site strategy. While some of that’s provided by Dropbox it doesn’t give me complete recovery in case of a fire. This is more important than ever now that most people’s pictures and audio are all electronically stored. This also represents TBs of data, so moving it offline is a real challenge. So far, I’ve found that IoSafe provides the simplest solution for me. We reviewed this hard drive last year. It’s a fireproof, waterproof and crush-proof hard drive. In my strategy, about once a month I connect this drive and run a SuperDuper backup to it.

That about covers it. If properly implemented this strategy should give you the ability to recover in less than a few minutes with almost no data loss. Combine that with the IoSafe hard drive and your data should be safe no matter what happens to you, to your laptop or your home.

George Crump, Senior Analyst