I received many similar emails from you following last week’s article describing Time machine setup. I’d like to respond to those questions here just in case more of you had the same questions but didn’t write in.
The most common question was about partitioning the drive. If you have been using a drive for Time Machine, you don’t need to go and partition it now; that is already done. You also don’t need to partition the drive if it comes pre-formatted for the Mac. Most external drives are set up for PCs and will need to be formatted, and I also recommend formatting any LaCie drive to get rid of their proprietary backup software that doesn’t work with Lion. Other hard drive manufacturers bundle their own proprietary software, and in all cases this software can’t begin to touch Time Machine’s powerful elegance. Partitioning (read: erasing) the drive gets around all this.
Another question was about backup frequency. If Time Machine is set up properly, and the drive is plugged into the computer, you’ll get a backup every hour. If you are backing up over a network this can slow your network down while the backup is being performed. You can find a utility program called Time Machine Editor that allows you to schedule your backups. I do this for mine so it backs up at 3 am every day rather than every hour. This will not do a full system backup every time; after the initial backup, only incremental changes to your drive will be backed up. So if it does a backup at noon and between Noon and 1:00 you’ve edited a document that document will get backed up and Time Machine will keep the noon version and the 1:00 version.
The third most common question was about the amount of backups and drives getting full. Time Machine will get you those hourly backups till there isn’t enough space left on the drive. At that point it will delete the oldest backups until it has enough space. You can set it up to warn you or just delete depending on your preference. You can periodically archive your drive either by cloning it to a second external drive using Disk Utility or a program like SuperDuper. If you’re running a Time Capsule you can connect a second drive to that device and archive it through the setup utility.
Fourth in the list was about viewing and using files. Apple did not intend the backup to be used in Finder. You should be entering Time Machine through the menu item on the top of your screen. This will bring you into the backups for whatever the front most application is. So if you need to restore a picture from iPhoto you’d launch iPhoto, then enter Time Machine, then navigate back in time till you find what you’d need then click the restore button. It’s as easy as that. It also makes more sense once you’ve tried it. If you navigate through the file structure of the drive you run the risk of grabbing incomplete files depending on how those files changed over the course of Time Machine backing them up.
The last question was about using the Time Machine drive for storing other information. I would strongly urge you not to do this. In an ideal situation a backup drive is used for nothing other than backups. This would also be a drive that is not moved much. The act of copying and reading data are putting stress on the drive and slowly decreasing its lifespan. With a backup drive you want to minimize this as much as possible so that drive outlives your main drive. Just because it’s a backup drive doesn’t mean that it will never fail.
I hope this answers all your questions.