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ATPM 16.12
December 2010


How To



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How To

by Sylvester Roque,

Updating Multiple Macs: the Combo Update Is Your Friend

The holiday season is upon us again. Time to remember the things we have to be thankful for and perhaps do a little gift-giving. If you haven’t already become one of the many Apple households with more than one computer, maybe this will be your year.

In modern society, there are many good reasons for being a multi-computer household. I hate to admit it, but there are probably some good reasons why one of those machines would be Windows-based. This month, though, I would like to focus on those of us who have, or support, multiple Macs. There are some things that you can do to make the whole process much more enjoyable and productive.

Setting Up User Accounts

If you’ve used a Mac for any length of time, you’ve probably had to set up at least one user account. The process is pretty straightforward, and if it’s the initial setup your Mac will walk you through the process. If you are going to be setting up or managing multiple Macs in your home, there are some things you can do to make things easier.

Not Every User Needs to Be an Administrator

Every Mac must have at least one user account designated as an administrator account. Without an “admin” account, such basic tasks as installing software can’t be done. That does not mean, though, that every user needs administrator privileges. Do your children, for example, understand the system well enough not to delete or move files that you don’t want moved, such as your iTunes library? Users who don’t have at least a basic understanding of OS X could wreak havoc on a system if they have an admin account.

Create a Troubleshooting Account

Create a troubleshooting account on each Mac. It doesn’t have to be named “troubleshooting,” but it does need to be an “admin” account. Don’t use this account for daily computing; save it for times when you are having problems. Let’s suppose one of your programs is behaving erratically when launched from your main account. Log into the troubleshooting account and launch the same program. If it runs properly there, the problem may be a corrupt preferences file for that program in your main account.

Create the Same User Account on All Machines

The small number of people with regular access to our Macs have their own user accounts. I’ve duplicated the accounts across both machines. With this setup, there are fewer passwords to remember. Additionally, there are fewer instances of the operating system complaining that I don’t have sufficient privileges when I move a file from one system to another. I usually migrate the user accounts by using Migration Assistant, but you could create the accounts manually. If you go the manual route, it is probably best to create the accounts in the same order on each machine.

Practice Good Account Security

Encourage users to log out of their accounts when they are not being used. Without that measure, anyone with access to the Mac can move or delete files. Although your family wouldn’t do that deliberately, accidents happen to the best of us. Leaving the computer logged into a specific user essentially means that anyone with physical access to the computer can see and modify that user’s files.

While we are on the subject of account security, make sure the login information for each user is not somewhere where just anyone can find it. It does no good to encourage your family to log out of their accounts when they are not used if the user name and password are written on a sticky note attached to the monitor.

The Root User Is Usually Not Your Friend

One of the concepts that OS X inherits from Unix is that of the “root user.” This special user has read/write access to the entire filesystem. Thankfully, Apple has this user turned off by default. Personally, I wouldn’t enable it unless absolutely necessary, but before you make that decision, read Apple’s comments about the root user.

Advantages of the Combo Updater

When I first started using Macs we had one machine, and I think the current OS was some version of System 7. At some point between then and the release of Mac OS X 10.0, I noticed that you could install a version of the OS that was sort of “generic” and would boot most machines. It was a great idea for troubleshooting. I thought we had lost this ability in Mac OS X until someone on the ATPM staff pointed out that the “combo updater” serves that purpose nicely. With Software Update in place to regularly identify updates, what is the “combo update” and why use it?

Apple currently uses two general types of OS updates. Individual updates are those identified by Software Update and may be specific to each type of Mac. For the last several updates, the version identified as appropriate for my desktop Mac Pro has been a different size from the one identified as appropriate for my MacBook Pro. Combo updaters on the other hand, “update the base version of a Mac OS X release to the version specified in the Combo Update, including all intermediate updates.” Using the current combo updater, one could go from 10.6.0 to 10.6.5 without installing each of the point releases.

While you could use an individual update to perform the same task, there can be problems. Sometimes an individual updater depends upon some other component, such as a security update or installer update, already being installed and current. If the right files aren’t found, and current, they generally must be installed first before further installations can proceed. This often means that additional restarts are needed. This is one of the primary advantages of the combo update: it updates most of the critical OS components in one download without worrying about the sequence of installation.

While the file sizes for combo updaters are sometimes quite large, if you are not good about keeping up with updates they are often the same size or smaller than downloading all of the component parts. It seems to me to be so much more Mac-like to download one file than to download several files and worry about the installation sequence and possibility of multiple restarts. Repeat that process over multiple Macs, and you can see how the combo updater starts to look more efficient.

There is one other advantage of using the combo updater, but it is not specific to multiple-Mac situations. I don’t recall ever having an OS update completely fail to apply properly when run through Software Update, but apparently other users have experienced this problem. Many of them have also reported that applying the combo updater resolved whatever was preventing the update from installing properly.

Tips for Using the Combo Updaters

After you have started using the combo updaters, Software Update is still a useful tool. If you’ve decided that you want to make use of the combo updater, that doesn’t mean that Software Update is useless. It can be configured to check for updates automatically, which means you don’t have to remember to check manually. Once it alerts you that an update is available, you can always manually download the combo updater.

Make sure to grab the appropriate combo updater for your situation. Don’t grab the Snow Leopard updater, for example, if you are not running at least Mac OS X 10.6. There seems to be a somewhat common misconception about the updates that Apple has available for download. These downloads cannot be used to skip an entire series of the operating system. You must have the base operating system installed in order for its associated update to work The recent 10.6.5 (Snow Leopard) update will not update a Mac running 10.5 (Leopard), even if the Mac has enough horsepower to run Snow Leopard.

In order to keep from downloading the updater several times, I download it once and move the installer from one machine to another as needed. You could burn the installer file to a CD or pass it from one machine to another via the network, but I usually use a small portable hard drive that I had taking up space. That’s often faster than burning a CD or using the network, but use what you have.

Once you have applied the combo updater and restarted if necessary, run Software Update on each Mac just to make sure everything is current. This is a great way to catch minor changes in software that are specific to a system. My desktop Mac, for example, has an older version of iLife, while the laptop has a current version. By running software update regularly on each machine, I don’t have to keep track of which version needs to be updated.

Final Thoughts

This process could be applied to other software that is common across all of your Macs, such as iTunes. The time savings may be a bit less, though, since these updates are often smaller. If you have a slower Internet connection, this process can still be a time saver since you don’t repeatedly download the same files.

I have focused this month on setup and updating issues associated with multiple macs in the same household. The inspiration for this came about with the recent release of an update that was several hundred megabytes. There were other issues that I haven’t addressed, such as keeping data in sync, that might be addressed in the future if there is some interest.

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