Upgrading your Mac’s operating system is a bit like removing your house’s existing foundation to add a new garage underneath. In both cases, the procedure is conceptually simple: set aside the parts you want to keep; remove some old pieces; add some new pieces; replace the original structure onto the new foundation; and reconnect all the infrastructure that was severed in the process. Assuming all goes well, the final product is more stable and has wonderful new features.
In the case of Mac OS X 10.4 Tiger, tens of thousands of pieces—the files that make up the operating system and your data—must go into just the right places with just the right settings. Ensuring that this happens is the job of the installer application, which knows what needs to go where. Apple wants you to think of the process as a simple one: double-click the installer, answer a few easy questions, wait for the installation to complete, and enjoy your new operating system. And to its credit, Apple has made some wonderful improvements in the Tiger installer that promise to eliminate many frustrations of earlier upgrades. Many users will have just the sort of trouble-free upgrade we all hope for.
Even so, a major system upgrade such as this one is a complex operation with many potential pitfalls. Problems can and do occur. Some users will find that they can’t complete the installation process but won’t know why: Some will be unsure which options to choose, or what effect they’ll have. Some will be unable to reboot their Macs after the installer finishes. Some will be unable to print or access the Internet. Some will lose important data, encounter software incompatibilities, or find that their peripherals no longer work. I’ve run into all these problems and more at one time or another, and I want to spare you such inconveniences.
An important note before we begin: As with any major system upgrade, make sure you have a current backup before proceeding. Take Control of Upgrading to Tiger contains additional advice on preparing for the upgrade and solving problems you may encounter.
Choose an Upgrade Method
For users with an earlier version of Mac OS X already installed, the Tiger installer offers three upgrade options:
Upgrade Mac OS X (the default upgrade method)
Archive and Install
Erase and Install
You will select one of these methods later, when you run the installer, but you should know about them now, because the method you choose will determine some of the other preparatory steps you must take. Most users will opt for the default choice, assuming that Installer Knows Best. In an ideal world, this would be the most painless upgrade. Unfortunately, with every new system upgrade, some users who choose this method run into serious problems—especially if they don’t prepare for it properly.
(If you install Tiger onto a volume that does not already have a Mac OS X installation, the Upgrade Mac OS X choice becomes Install Mac OS X. This option installs a clean copy of Tiger on the selected volume, but does not erase any other files that may already be present there.)
In Take Control of Upgrading to Panther , I recommended Archive and Install (with some modifications) for most users. With Tiger, however, Apple has added a new file transfer capability that makes Erase and Install a more attractive option for many users—while also presenting you with an array of potentially confusing options. Ultimately, your choice of upgrade method will depend on your Mac setup.
Upgrade Mac OS X
The default method, Upgrade Mac OS X, attempts to make the transition as simple as possible by leaving all your files, applications, and settings in place. The installer replaces all the components of your old Mac OS X installation with their Tiger equivalents, and deletes those that are obsolete. Meanwhile, it leaves all user-installed files (including preferences) intact.
Sounds great, doesn’t it? In theory it is, but this approach can lead to serious problems. Most importantly, some of the third-party software you have installed may conflict with Tiger. When you restart after installing Tiger, if a serious conflict exists, you may experience a system-wide crash known as a kernel panic , application crashes, indecipherable error messages, or other malfunctions. Other customizations you may have applied to your old operating system, such as command-line hacks, can also cause problems for Tiger. Even a disk error that never showed itself under Panther can manifest itself after a default upgrade.
To be fair, not every user is at risk for problems with this sort of upgrade. If you’ve never installed any non-Apple software or modified your system beyond documented preferences, your chances of problems are low. This is especially true if you have a very new Mac, or if you performed a clean installation of Panther recently.
The more modifications you’ve made, and the longer you’ve gone since a major operating system installation or upgrade, the greater the risk of problems with this method.
Archive and Install
Starting with Jaguar, Apple introduced an upgrade method called Archive and Install. This is similar to the Clean Install method available in Mac OS 9, but more advanced. Archive and Install creates a completely new, clean system but maintains a copy of your old system files so you can manually copy over any important items after the new operating system is up and running.
Archive and Install includes an option called Preserve Users and Network Settings. If you select this (and you should), Archive and Install leaves your home folder(s) (the contents of the /Users folder) in place, so that documents, preferences, and network settings for all user accounts are maintained after the upgrade.
Note: The Tiger installer claims that if you select Preserve Users and Network Settings, you will skip Setup Assistant when installation is complete. This isn’t quite true: it does run, but in an abbreviated form—it asks only for your Apple ID and registration information, and doesn’t take up the whole screen as it does normally.
Archive and Install avoids most compatibility problems because the installer does not copy the contents of your old System folder (including third-party extensions and login items) to the new system; it also skips several other folders inside /Library and at the root level of your disk. Although Archive and Install is not foolproof, it’s much more reliable than the default method, Upgrade Mac OS X.
The downside to Archive and Install is that this method requires some manual effort afterward to locate and copy the extra files you need. In some cases—particularly if you have a lot of third-party utilities, fonts, and other software—this can be a huge and frustrating amount of manual effort. Archive and Install also requires a significant amount of free disk space, because it must maintain an extra copy of many old files. But the reward for your efforts will be a cleaner, more stable system and a far smaller likelihood of having to do time-consuming troubleshooting.
Archive and Install should be available as an option both in the full version of the Tiger Install DVD and in the upgrade DVD available through the Mac OS X Up-to-Date program.
Erase and Install
For a perfectly clean, pristine installation of Tiger, you can choose Erase and Install, which all but guarantees a fully operational system when the installation finishes. Unlike the other two installation methods, it wipes out any hidden directory corruption, file system problems, or other disk gremlins that may cause problems.
Of course, there’s a price to pay for a perfect system: all your preferences, network settings, user-installed software, and documents will be gone, and you must either restore them from a backup or recreate them from scratch. Depending on how many changes you’ve made to your system, this may be a daunting task.
That’s where Apple’s new file transfer feature (a.k.a. “migration technology”) comes in. Immediately after an Erase and Install, Setup Assistant runs automatically and offers to copy all your personal files from another volume (or even another Mac). If you’ve made a bootable backup onto an external hard disk or another partition on your internal drive, the installer will do 90 percent of the copying work for you. (And the other 10 percent? See the
Restore Missing Files section at the end of this excerpt.) Erase and Install also requires much less disk space than Archive and Install.
Erase and Install is ideal for users with an external hard drive (or two) that can be used for backup. It is also the best method if your hard disk has errors that Disk Utility is unable to repair or if you’re simply paranoid and want to avoid any chance of problems.
Note: Erase and Install erases only the volume you select. It will not affect partitioning or wipe out the contents of other partitions.
File Transfer Vs. Archive and Install
If you were to compare two systems side-by-side—one upgraded using Archive and Install, and the other using Erase and Install (with all options selected on the File Transfer screen)—you would find that Erase and Install transfers many more files and folders to the active system. If you use Archive and Install, you’ll have to transfer all the rest manually. To avoid that effort, I recommend using Erase and Install, along with the File Transfer feature, if possible.
Which Method Is Right for You?
The choice of Upgrade Mac OS X, Archive and Install, or Erase and Install comes down to a few simple factors.
Choose Upgrade Mac OS X if:
You have never installed any non-Apple software on your Mac; or
You recently performed a clean installation of Jaguar or Panther; or
You have a new computer to which you’ve made few changes; or
You want to gamble. This is the fastest method of installing, if all goes well. However, if all does not go well, it is the slowest. (See Joe’s Compromise Method
on the next page for a way you can potentially have your cake and eat it too.)
Choose Archive and Install if:
You do not have the means to duplicate your startup disk onto another volume; or
You are technically inclined and wish to copy non-critical files into your new system manually (as a way of doing some spring cleaning, for instance); or
You’re nervous about the potential compatibility problems with Upgrade Mac OS X—and equally nervous about wiping everything off your hard disk with Erase and Install.
Note: If you choose Archive and Install, be sure the Preserve Users and Network Settings checkbox is selected (as it should be by default).
Choose Erase and Install if:
You have an external hard drive (or a second internal drive) with enough space to duplicate your primary volume; or
You have severe disk problems that Disk Utility cannot repair; or
You have very little free space on your internal disk; or
You are paranoid about problems that could occur with other methods and want the best possible chance of upgrading success.
Double Serious Don’t Say We Didn’t Warn Your Warning!Take Control ’s publisher, Adam Engst, who is a major wuss when it comes to erasing hard disks, has asked me to remind you that Erase and Install really will destroy all the data on your hard disk (or partition) prior to installing a fresh copy of Tiger. If anything were to go wrong with your backup, you would be very unhappy. (Adam would have at least two independent backups before starting). So check and double-check your backups before you proceed!
All things being equal, I prefer Erase and Install because it offers the best combination of robustness and ease of upgrading. It does require, in most cases, that you have a second hard drive in order to back up your primary volume; even if you’re backing up your data to a separate partition, you will want a second drive to hold your data during the partitioning process. But then, I can think of many good reasons to purchase a second drive—especially if it’s an external FireWire drive, which makes a superior backup device.
Joe’s Compromise Method
I know that a lot of people reading this ebook are thinking to themselves, “Yeah, I realize I probably should do an Archive and Install or an Erase and Install, but those seem like a lot of work, and probably nothing will go wrong if I just go with the default method, Upgrade Mac OS X. If it works, I’ll save a lot of time!” That is certainly true, and I don’t mean to frighten you into thinking your computer will blow up if you do things the easy way. Most people who stick with the defaults will have a perfectly good upgrade experience.
But then, some people will have extremely bad experiences. My goal is to help you minimize the risk of things going wrong and maximize the chances of everything going right!
So for those of you who are perhaps a bit reluctant to make extra work for yourselves, allow me to offer a compromise between the simplicity of Upgrade Mac OS X and the safety of the other two methods:
1. Follow my suggestions in the other sections of this book (Disable Login Items, Back Up Your Data, Verify Your Hard Disk, and so on).
2. You did back up your disk, right? Check it. Double-check it. Be absolutely certain you can restore your startup volume to its pre-upgrade state if the need arises.
3. When the time comes to select an upgrade method, choose Upgrade Mac OS X.
4. After the upgrade, be sure to follow the steps in the Run Software Update and Set Up Your Tiger Environment of this book.
5. If anything goes wrong during this process (your computer does not boot, applications crash, etc.), use your backup software to restore your startup volume to its earlier state, and then perform an Archive and Install or Erase and Install.
Your Mac will now be running Tiger—and you just may have saved yourself some time and effort.
Restore Missing Files
( Note: If you selected Upgrade Mac OS X as your installation method, this section doesn’t apply to you.)
As I mentioned earlier, whether you use Archive and Install (and its Preserve Users and Network Settings option) or Erase and Install (transferring user files, applications, and documents from a backup volume), the installer does not copy all your old files. To some extent, this is a good thing—many of the files not copied are the ones most likely to cause problems after upgrading. If you were going to copy all the old files anyway, you might as well have chosen Upgrade instead; you gain little from Archive and Install or Erase and Install.
That said, many users will find that they need some of these items. To complicate matters slightly, the list of files not copied into the active system differs depending on whether you used Archive and Install or Erase and Install. Here are a few prominent examples of missing files.
Not copied during Archive and Install or Erase and Install:
Drivers for peripherals such as mice, scanners, and audio equipment and other system enhancements packaged as kernel extensions (located in /System/Library/Extensions)
Any user-installed files inside /usr—including the entire /usr/local directory, which may contain Unix software such as MySQL (and its data)
Files you may have modified inside /private/etc, such as /private/etc/httpd/httpd.conf, the Apache config file
Copied during Erase and Install but not copied during Archive and Install:
Third-party preference panes that were installed in /Library/PreferencePanes (as opposed to a user’s ~/Library/PreferencePanes folder)
The /Library/CFMSupport folder, which contains components needed for Palm synchronization
The contents of /Library/Components, which may include files required for utilities such as TypeIt4Me and iGlasses
The contents of /Library/Frameworks, including components used by PGP Personal Desktop, StickyBrain, Stuffit Deluxe, iODBC, and other software
The /Library/OpenBase folder, used (and installed) by applications such as StickyBrain
You can restore some of this software to your Tiger system simply by running the installers again; in other cases, you must manually copy the files from your backup volume (if you did an Erase and Install) or your Previous System folder (if you did an Archive and Install). Begin by reinstalling affected software packages. Afterward, you can manually copy any remaining files you still need.