Chapter 6. Using Backup

6.1 What to Back Up?

If you've never done a backup before, figuring out what you should back up is the first hurdle you'll need to overcome . There are two types of backups you can perform:

• A complete backup , which means that you backup everything on your hard drive, including the system software.

• A partial or incremental backup , which means that you will only backup certain files.

For example, long-time Mac users know the importance of keeping a backup floppy of your Preferences folder ( /System Folder/Preferences ). With earlier versions of the Mac OS, the greatest source of startup problems had to do with extension errors, which often traced their way back to a corrupt preference file. If you had a recent copy of your preferences, you could simply pop in your backup floppy, drag the Preferences folder onto your System Folder, and restart. Sure, you'd lose any preferences that were set since the last backup was made, but at least you could get into your system. If you backed up your Preferences folder once a week, the risk of you being locked out of your system reduced greatly. In that case, the act of dragging the Preferences folder onto a floppy disk would be considered a partial backup .

What you back up depends very much on how you use your system, and how important you determine its data to be. For me, my Mac is my life. If my hard drive were to crash and burn, or if my house were broken into and my Mac were stolen, my only recourse of getting my information back is having a complete backup. But I also do partial backups as well.

Confused? Don't be. This is a fairly standard practice.

Backing up your entire system can be time consuming, but it's worth it. For me, I typically do a complete backup once a week on Sunday, and partial backups nightly. The weekly backup saves everything on my hard drive to a set of CDs, while the nightlies save specific folders to an external FireWire drive connected to my PowerBook. ^[1] That way, if my system crashes midday on Wednesday, I can restore my system to the complete backup performed on the previous Sunday, and then restore files from Monday and Tuesday's nightly partial backup. Without the combination of complete and partial backups, who knows how much work I would have lost, and trying to remember what I've edited or written in a week is impossible , let alone the emails.

^[1] I also back up files to my iDisk daily, but the backup to my iDisk is limited to just a few things, mainly for redundancy.

Backups ”both complete and partial ”are a way for you to protect yourself from partial or permanent loss of data. Take the time to consider what's important to you, and back it up accordingly .

At a minimum, some things you should consider backing up include:

Email

Depending on how much mail you receive in a day, you may only need to back up your email on a weekly basis. However, if you receive a lot of email and it's a critical part of your daily communications, you should consider backing it up every day. If you are using Mac OS X's Mail application, your mail is stored in ~/Library/Mail .

Preferences

Old habits never die. Backing up your Preferences ( ~/Library/Preferences ) can save you a lot of time from having to reset your application and system preferences if something goes amiss.

Home directory

Backing up your Home directory can simplify the task of selecting which files to back up. By selecting your Home directory to back up, you will catch everything in all of the directories you see in the Finder when you click on the Home icon. This includes the contents of the following folders:

• Desktop (only the files on your Desktop will be backed up, not the contents of any mounted drives )

• Documents

• Library

• Movies

• Music

• Pictures

• Public

• Sites

Mind you, if you have a lot of files, a complete backup of your Home folder can take a long time, and you probably won't be able to back up all of this onto your iDisk. However, if your Mac is equipped with a Combo or SuperDrive, you will be able to back up to CD or DVD instead, or to a networked or external drive that's mounted on your system.

These are just a few ideas of things you should consider backing up. One thing you don't need to back up, at least according to Apple, is all of the information on your iDisk. Apple makes nightly backups of all .Mac members ' iDisks.