backup is a backup with an archive. In this case, when you back up disk A to disk B, the old information on disk B will be moved into an archive, not deleted, which is particularly useful since you can go back in time and recover files that have been previously deleted from disk A. If you are more of a visual thinker, these differences are illustrated in Figure 7-1.
Figure 7-1.Differences between backups and synchronization
Generally, when you want to keep an extra copy of your important data in case something happens to your primary data store, then what you want is a backup. When you have two data stores that you need to keep current with each other, then what you want is synchronization.
Either way, you are creating a redundancy that is important should one data source fail. One important note, though: creating a backup with archiving is the only way to effectively protect against file corruption. If you synchronize or simply back up a corrupted file, then you are just creating a new copy of a corrupted file, often overwriting an old, noncorrupted file.
Backing Up Your Data with Time Machine
Leopard introduces what seems to be a fantastic little backup utility called Time Machine. Time Machine provides data backups of all your information complete with a historical archive of data. The best thing about this, though, is that Time Machine does all of its work automatically in the background, making it painless. The disadvantage, though, is that in order to use Time Machine, you will need an extra hard drive connected to your computer for Time Machine to back up data to.
NOTE When deciding whether to invest in an external hard drive for Time Machine to use, ask yourself how much the data you keep on your computer is worth. You can easily find a nice- sized external hard drive these days for less than $100, and in our opinion, our data is worth at least that.
NOTE If you are desperate, you can set up Time Machine to back up to a different partition on your primary hard drive. Although this will provide some protection of your data as well as a nice historical archive of data, this will do nothing if your hard drive fails.
To set up Time Machine, you open the Time Machine pane in System Preferences (Figure 7-2).
Click the Configure button to pick an attached volume for Time Machine to use, and then, if you’d like, add any volumes or folders you don’t want Time Machine to back up. Finally, you have the options of skipping backing up system files and having your backup occur automati- cally. Skipping system files isn’t such a bad idea, since if something really bad happens, you’ll need to reinstall the system anyway and you have that on your DVD. The automatic backups are a personal preference. If you remember to back up manually (by clicking the Back Up Now but- ton), then that’s fine. If, however, you just don’t want to think about it, leave the automatic backup checked.
Figure 7-2.The Time Machine preference pane provides configuration options for Time Machine.
NOTE Once Time Machine is active, you can select individual items within the Finder and choose whether to include or exclude them from Time Machine backups in either the Get Info window or the contextual menu.
Once Time Machine is initially set up, it may take a bit of time to make the initial backup, but after that, the backups will be relatively short (unless you are doing backups manually and infrequently or you use a portable and attach your backup drive only every now and then).
However, once things are moving, Time Machine is ready when you need it.
When you launch Time Machine, your desktop will fade away, and you will be brought into the Time Machine interface. If you launch Time Machine from the Finder, then a Finder window
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will be the main focus (Figure 7-3). You can navigate through the single Finder window nor- mally, and you will find all the currently backed up Finder items. If you go to the far-right side of the window, though, you will notice a time line. If you click back through the timeline, the Finder window will change from showing you the latest backup files to showing you the files backed up as far back as you go in the timeline. If you want to restore any file from any time or place in the Finder, simply select it, and click Restore at the bottom. This will bring the item out of Time Machine and put it back in its original location in the Finder. If an item of the same name exists in that place, then you will be prompted to keep one or the other files or both files.
Figure 7-3.Time Machine browsing Finder items as they were backed up through time
NOTE The timeline will go back pretty much as far as you let it. When you click the Configure button in the Time Machine preference pane, there is an option to delete files after a certain amount of time. If your backup volume is low on space, you may want to utilize this.
If you want to leave Time Machine without restoring any items, just click the Cancel button in the lower-left corner of the Time Machine interface.
One interesting aspect of the Time Machine is it will attempt to open Time Machine in the frontmost open window on your screen. If you double-click the Time Machine icon in your Applications folder, the Time Machine will open with a Finder window open to the Applications folder. On the other hand, if you are working in a Time Machine–enabled application and you open Time Machine from the Dock (either from an icon on the Dock or from a stack), an inter- esting thing will happen: instead of getting a Finder window, you will get an application window that you can browse backward through and restore changes in that application. For example, if you launch Time Machine while running the Mail application, then Time Machine will open with a Mail window (Figure 7-4), allowing you to go back in time and view old mail messages that have been deleted.
Figure 7-4.Opening Time Machine while Mail is running in the foreground opens Time Machine in Mail, allowing you to recover deleted Mail messages.
If you ever need to recover more than just a file or a few e-mail messages, Time Machine allows you to select and recover entire folders, or, yes, even your entire volume. Additionally, if you even have to reinstall your system from scratch, there is an option during the install that will recover information from a Time Machine backup disk (you can learn more about installing Leopard in Appendix B).
NOTE Many people may point out that Time Machine actually goes beyond just backup and actually provides version control as well. Version control tracks changes of items over time so that you can recover older versions if something critically wrong happens in a new version. For developers, version control (or source code management [SCM]) is essential for creating stable software, and support for a number of version control systems including CVS, Subversion, and Perforce are built into Xcode. For more general project version control, Versions (www.
versionsapp.com/) provides an easy-to-use interface for taking advantage of the Subversion version control system.
Synchronization
Besides backup, Leopard provides a number of ways for you to sync your data with the other computers or devices you use.
First there is iSync (Figure 7-5). iSync allows you to sync your calendars and your contacts with mobile devices. So if you are out and about and meet an old friend and enter their contact information in your phone, next time you sync your phone using iSync, that contact information will be added to your Address Book. At the same time, if you add a number of events in iCal, when you sync your phone with iSync, those events get entered into your phone’s calendar.
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Figure 7-5.iSync allows you to sync contacts and calendar information with mobile phones and PDAs.
To use iSync, first you must connect an acceptable device to your computer (you can find an up-to-date list of devices that are supported by iSync at www.apple.com/macosx/features/isync/
devices.html). Once the device is added and recognized, it will show up as an item in iSync’s tool- bar. Selecting a device will allow you to set up the sync options. You can choose what items you want to synchronize and how to handle the initial sync. To start the synchronization process, hit the Sync Devices button in the top-right corner. If your device is found and ready to receive (you may need to do something on the receiving device as well), then the sync should occur. You will be notified of any errors as well as how many items have successfully been synchronized.
iSync is also used to synchronize your data with .Mac, but today .Mac allows all sorts of interesting synchronization options that far outshine iSync. .Mac (which is covered in more detail in Chapter 15) allows you to selectively sync a wide number of items from your computer through .Mac to any other computer. For example, if you use a Mac at home and a Mac at work, then through .Mac you can keep the following items synced with each computer:
• Bookmarks
• Calendars
• Contacts
• Dashboard widgets
• Dock items
• Keychains
• Mail accounts
• Mail rules, signatures, and smart mailboxes
• Notes
• Preferences
• Entourage notes
Together these options effectively re-create the environment from one computer to another and then keep the environments in sync with each other, creating a seamless transition from working with one to working with the other.
The items you want to keep synced must be selected for each computer you want to keep synced. This can be set up and configured on the Sync tab of the .Mac pane of System Prefer- ences (Figure 7-6).
Figure 7-6.You can use .Mac to keep the environments of two or more computers in sync with each other.
NOTE One unique yet extraordinarily common sync is syncing an iPod or iPhone. Both of these sync from within iTunes. This particular case will be covered with iTunes in Chapter 14.
Other Methods of Backup, Sync, and Recovery
Besides these methods that are part of Leopard, you can use a range of other utilities, applica- tions, and methods to protect your data. Some applications, such as Apple’s Aperture, provide a means of backing up and archiving their data. Some people are in the habit of regularly burning archives of important files to CDs or DVDs, and there are many other applications out there to help with backup and recovery of your data. If Time Machine doesn’t quite fit your needs (or for whatever reason you just don’t like it), these are some other applications worth a look:
• Decimus Software (www.decimus.net/) makes three different backup applications depending on your needs: Synk Backup, Synk Standard, and Synk Pro. These apps range in cost from $25 to $45. Although the Standard version handles most common backup and synchronization tasks, the Pro version adds some very nice features and at $45 is the best bang for your buck.
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• Qdea (www.qdea.com) has been making backup software for Macs for years. Their current Synchronize! X Plus and Synchronize! X Pro are also great products for a variety of backup and synchronization needs. These cost $29.95 and $99.95, respectively.
• EMC Insignia (www.emcinsignia.com), a division of storage powerhouse EMC, recently acquired Retrospect, a highly regarded backup solution for Macs. EMC Retrospect for Macintosh comes in four versions. The Express version, which is distributed only with hard drives from some manufacturers and resellers, provides basic backup capabilities.
The Desktop version (about $120) provides everything you could want in a desktop backup solution. The Workgroup version (about $500) is designed to keep up to 20 networked computers all backed up. The Server version (about $800) provides backups for up to 100 desktop clients (this version supports clients running Macs, Windows, and Red Hat Linux).
What’s most important—whether you use Time Machine, use Retrospect, or manually copy all your data onto thumb drives—is that you do something to back up your data. Just pick a sys- tem that works for you and go with it.
Summary
Now that you know how to protect your data from hard drive failures and accidental data loss, we’ll move on to protecting your data and your computer from other threats.
Besides protecting your data from hardware failure and accidents, in today’s world, where computers tend to be always connected, it’s also important to protect your data from other users—both on your computer and outside of it. This chapter deals with security, including the following topics:
• Passwords and keychains
• Data encryption and FileVault
• Other security features
Passwords and Keychains
Passwords are used time and time again on your computer: logging in to your account, checking your e-mail, visiting certain web sites, logging in to connected servers, and more. There are so many passwords that it becomes a chore to keep track of them all. To help manage all of your passwords, security certificates, and encryption keys, OS X includes a keychain feature to keep track of all of this information.
The Keychain Feature
Whenever you enter a password into an application that takes advantage of the OS X keychain, you will be prompted whether to save the username-password combination in your keychain. If you select yes, then the next time you log in, rather than getting a prompt to enter your username and password, the application will automatically use what’s already saved in your keychain.
Now your keychain will only use the passwords stored in it under certain circumstances:
• The keychain will only use data saved in the logged-in user’s keychain, so your keychain is protected from all other users (excepting shared keychains).
• By default, passwords associated with a particular application allow only that application to access the password item in your keychain. Often when you update your application and attempt to use it, you will be prompted to update the key to work with the updated application (you will need to authorize the update).
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Leopard Security
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