Adding to your comments for laptop users…

I would recommend for all users that for significant downloads like security updates or OS X updates it is also a good idea to use SW Update to only download — and not install — the update (or any others that require a restart). This allows the user to perform installations at a more convenient time and is a hedge against power failure or loss of Internet connection. To do this, first select the update(s) you wish to download, then choose Download Only from the Update menu.

This is also handy if updating multiple machines (from the same updater when running similar hardware and software on each Mac). Another benefit comes if you wish to reinstall later, you don’t have to download it again as it’s already on your hard drive.

To head off most System problems before they occur, I have found it is always best to ignore Software Update for System Updates. It makes for a good “heads up” that the Update is available, but it really is NOT the best way to update your System. The best method for a clean System is as follows:

- Go to Apple Downloads ( http://www.apple.com/support/downloads/ ), where you will usually have a choice between (for example) “Mac OSX 10.5.2 Update,” or “Mac OSX 10.5.2 *Combo* Update”. Choose the Combo Update even though it’s very much bigger, and takes longer to download. It contains everything new that was ever added to the original System version -in this example, 10.5.0, and reinstalls it in a shiny new, uncorrupted, pristine condition.

- Open Disk Utility and Repair Permissions on the hard drive targeted for Updating. You should also do this for anything you are installing that affects the System, including Security Updates.

- Open the downloaded Disk Image of the System Updater and drag the Installer to your Desktop, then run the installer from there.

- You will be asked to Restart, so do it.

- As soon as your Mac reboots fully, but before you do anything else, open Disk Utility and Repair Permissions on the hard drive you just updated. Again, you should do this also after any other installed System-affecting software.

- At this point, most folks will drag the Installer from the Desktop to the Trash. I say, save it somewhere, and I will tell you why. If things start to get really glitchy at a System level, you can just follow the steps above, reinstall this Combination Update and nine times out of ten, your problems will go away. I also save the latest Security, QuickTime, Airport, etc. Updates for the same reason.

My 2¢

I agree wholeheartedly with Jack on the combo updates. In my experience incremental (or delta) updates generally work fine, say from 10.5.1 to 10.5.2, but combo ones seem to be more reliable at keeping your system running smoothly. That is, users apparently report fewer problems after using them. If/when problems have been reported with system updates, you can pretty much bet that reports on the Mac web will reveal rerunning the installation with the combo updaters has cured many issues. Combo updaters can also be useful if updating multiple machines with different flavors of Leopard (or Tiger or whatever). For example, one 10.4.11 combo update would enable you to update machines whether they are 10.4.0, 10.4.1, 10.4.2 … up to 10.4.10. Just be mindful of your hardware (PPC updates will not work on Intel; for that you would need the Universal equivalent).

I would respectfully disagree re: repairing permissions. While permissions repair can be helpful, it would be also be safe to wait until after any software installation. It doesn’t hurt to repair before and after, but it is also redundant. Dan Frakes at MacWorld wrote an excellent article about repairing permissions in OS X in August 2006, and the lessons still apply. I’ve since followed his advice and have not experienced any problems. You can check out the article here: http://www.macworld.com/article/52220/2006/08/repairpermissions.html

@Jack and @Eric, thanks for the posts, good data. I want to elaborate a bit.

My opinion on why people report better luck with the combo updates is that they are already in a state of problems. Re-applying the update, which is only possible with the combo update, fixes things, thereby giving the impression of it being a better method.

I tend to be a little more nuts and bolts, and want to know why one would work better than the other. Don’t get me wrong, I am not challenging your methods, by all means, whatever works best is absolutely the best method to go with.

I have a feeling the reason that some have issues with the auto software update method is something interferes with the update, and it does not fully install. The OS thinks it installed, so you never get a chance to install again if there are issues.

@Eric, thanks so much for the link to the repair permissions dance, I knew it would come up, and I am in agreement with you. Strongly. I am not at all saying you are going to hurt anything, but it is a dance I feel people are very religious about, with no technical merit to it.

Apple has a doc on the matter.

When you use Disk Utility to verify or repair disk permissions, it reviews each of the .bom files in /Library/Receipts/ and compares its list to the actual permissions on each file listed. If the permissions differ, Disk Utility reports the difference (and corrects them if you use the Repair feature).

So, the real issue here is sure, first, it is only fixing permissions on files. Second, we should not blindly just fix them, we should want to know what changed them in the first place. A file will never just magically have wrong permissions applied to it. Knowing what is causing the permissions change is a better plan than blindly fixing something that is going to continue to break over and over again.

Apple even changed the way repair permissions works, as it was harmful in the past when people ran it too often.

Anyone really interested in the “voodoo” that is behind repairing permissions, and why it is really not this panacea, should read these, they are very good, and technically sound articles:
http://daringfireball.net/2006/04/repair_permissions
http://daringfireball.net/2004/12/software_update
http://daringfireball.net/2006/04/repair_permissions_voodoo

If one downloads the combo updater, and looks at it’s inner file contents, you will see, it is more or less nothing more than the single updaters Apple is shoving out in the automatic Software Update tool. So, one for one, it is doing the same thing. Combo updates just give you a chance to do it again. And yes, I am being very simple for the sake of keeping this post somewhat relevant, so do not beat me up to bad on what really is inside the combo update package files

Thank you both for your comments, both are relevant, and neither method will cause you harm, but I did want to back up the data with some technical info so people are not blindly following advice. Example, I have never used a combo updater, and I never have had a problem with my system, and my system is pretty heavily hacked.

Thanks so much again to both of you for contributing.

This is my first time using OSX Help. It is written very clearly. I am very glad I checked you out. I will be using your helpful information.
I greatly appreciate this and look forward to other
OSX tutorials. E.

Scott- My iMAC is only 3 weeks out of the box and unfortunatley,I am also on dial-up so downloading anything, including software updates is problematic.
I have set my updates file to ;manual; for obvious reasons. My computer says it is running 10.5.2 but an update check says I need about 270Mb of updates, including security,Safari,etc.
I have temporary access to a hi-speed connection (at a friends home).Question: should I have my friend download the latest Combo 10.5.2 download onto a thumb drive–or do I need to drag my entire computer to his home (50Kms distant) and just download the items as reported by my computer? The combo update and the individual updates are suspiciously similar in file size. I am assuming here that the apple download site will not recognize my friends P.C. in order to download the individual items as reported by my computer. Thanx–J.P.

@jp, you bring up a great point, which is not everyone can even run these updates due to slow internet speeds. If you had a laptop, moving it around would not be so bad.

In your case, let me explain as best as I can how Apple’s downloadable updates work.

When you run Software Update, or even a downloaded Combo Updater, or Single Updater, it will install what is called a BOM, or Bill Of Materials. This is like a packing list, and is stored on your computer. In a simple form, it lists what Apple updates have been installed in the past.

The next time you run an installer, the first thing it does, is look at your computer, and use its internal BOM to compare to the previously installed receipts for other updates.

It will then install only what you need, or it may re-install on top. You do not entirely know. What you do know, is Apple does make it near foolproof to run software updates. If you need it, it will let it, if it is not harmful, it will let it, if you do not need it, or it is harmful, it will not be allowed.

So yes, feel free to download the combo updater and run it. As far as I know, you should even be able to do this on your friends PC, and the combo updater will work just fine.

Now what about software updates? Where does the .dmg files go once they are installed?

The reason for the questions is I want to save all the updates to the OS and apps so that if I need to install them on another Mac I don’t have to waste time downloading again.

I use Speed Download which has some advantages over the software update app.

@Mark, in general, once you have installed a software update, you can delete it. In this day of super fast downloads, a replacement is not far away.

If you have a slower download connection, you may want to save the dmg files. I would just pick a nice place to archive them on your drive.

Scott-Here we are a few weeks later–I downloaded the 10.5.2 Combo update using a friend’s hi-speed connection, thru his PC onto a USB drive. (along with a few other goodies). All the other goodies downloaded into the new iMAC just fine. The apple Combo update only went as far as “choose drive’ and proceeded to inform me that the file was larger than my entire drive! The USB drive is only 1GB, so now I’m really confused . Anbwords of wisdom?
Thx…J.P.

Scott:

Quick note here con the combo vs. the deltas:

It’s not voodoo (like the damned permissions process is). The larger the delta the more justified the combo.

Why is this? Because of deltas fixing problems by previous deltas and a thing called “Receipts”.

When you install a delta that may not leave things as nice as it should, the next delta usually fixes things up. It also fixes incorrect permissions (as they may come wrong, nothing to do with the “fix permissions” above and we’ll get to “why” in a moment) from previous deltas and makes sure defaults are what they should be.

When you install a delta that overwrites the previous delta it can only work with what it knows, it can’t account for all the things you’ve done in the meanwhile by yourself (or by applying “voodoo” tools like Onyx).

After installation every pkg leaves behind a Receipt. This receipt tells OSX what it’s done and what default states should be for everything (including, but not limited, to permissions). These receipts are used by the weekly and monthly routines of your mac to do basic maintenance.

When you install the deltas the processes need to go over the different Receipts and change things several times. Again not accounting for differences you may have unknowingly made between deltas (even trying to fix something yourself).

When you apply a combo you apple a single patch that leaves your disk as if you had just installed the original OSX disk and then applied a single patch. There are no piled-on changes. There are no accumulated user-modifications. There are no conflicting permissions.

This is the reason one of the first things Apple Support will do with a glitchy mac is applying a combo update on it.

Why “the larger the delta, the better the combo”? Because the larger the delta the more files from the previous delta are touched.

Also, keep in mind that a combo update updates any supported mac to the latest version of the OS. If you have more than one mac it’s already worth considering downloading a single updater, putting it on a pendrive and installing in all.

I also always put the latest combo in a partitioned external disk where I’ve loaded the Leopard installer, so I have one quick access to bring a mac up to speed to the latest version of the OS.

@jp

Scott-Here we are a few weeks later–I downloaded the 10.5.2 Combo update using a friend’s hi-speed connection, thru his PC onto a USB drive. (along with a few other goodies). All the other goodies downloaded into the new iMAC just fine. The apple Combo update only went as far as “choose drive’ and proceeded to inform me that the file was larger than my entire drive! The USB drive is only 1GB, so now I’m really confused . Anbwords of wisdom?
Thx…J.P.

I am not sure I totally understand the trouble you are having. I would suggest you copy the file off of the USB drive to your computer, and then run it. You then select your drive, and it will do the update process.

If the error you are getting is what I think it is, you could simply be out of space on your computer. The update will need a certain amount of space in order to run, you could be low.

Perhaps you can explain in more exacting detail what the steps were you took and the errors you are getting. If you could tell us how much free drive space you have as well, that may be helpful.

@eduo Thanks for your reply, I would like to comment and clarify a few things.

It’s not voodoo (like the damned permissions process is). The larger the delta the more justified the combo.

Why is this? Because of deltas fixing problems by previous deltas and a thing called “Receipts”.

When you install a delta that may not leave things as nice as it should, the next delta usually fixes things up. It also fixes incorrect permissions (as they may come wrong, nothing to do with the “fix permissions” above and we’ll get to “why” in a moment) from previous deltas and makes sure defaults are what they should be.

There has to be a reason an update, delta or otherwise, would cause a problem. It is my epxerience, they are very reliable. We hear they are less than reliable merely as a result of people tend to only report problems, and rarely report sucess. That is just the natur of near everything. While software updates can fix permission problems, they do not always do so, it depends on how the updater was made. If it has been told to perform a permissions repair, it will, if it has not, it will not. Just running an updater, delta or combo, does not always guarantee a permissions repair.

In the case of the combo updaters, they tend to ‘replace’ files, rather than ‘patch’ them, thereby the replcing action itself will change the permissions, perhaps correctly. I still stand by my initial statment that files do not magically change permissions, something changed them, and finding out what is better than running a permissions repair, or relying on an update to do so.

When you install a delta that overwrites the previous delta it can only work with what it knows, it can’t account for all the things you’ve done in the meanwhile by yourself (or by applying “voodoo” tools like Onyx).

Deltas in a technical sense to not everwrite another delta. Apple has several methods for supplying system udpates. Software update is the only way the updater app can try to make an intelligent decision as to what updates need to be installed. Generally in the form of a patch.

Combo updates do less patching and usually replace an entire application. This is why they are larger. If for example, mail.app is uddated, an applicaition that is hundreds of MB’s in size, the combo updater will be that at the least, that size as well.

I guess what I am getting at, is, simple security fixes are almost always small patches, I do not see a reason to wait on a combo update, and then download a huge updater.

Any updater, delta or combo, is really just a set of files, and the installer automates putting the files in certain places. Apple, like any other s-ware developer, uses Package Maker to make them. If you have ever built an updater, you can see it is just copying files around, and at times, running a pre or post flight script as well. You can easily disect an updater and see just what it is up to.

After installation every pkg leaves behind a Receipt. This receipt tells OSX what it’s done and what default states should be for everything (including, but not limited, to permissions). These receipts are used by the weekly and monthly routines of your mac to do basic maintenance.

Not entirely accurate. The receipt contains a bom, the bom is what tells OS X the file permission states of a set of files. I am not sure what other states you are refering to, but I would say the bom is in fact very limited, and it explains permissions, sizes, dates, and a checksum.

As far as I can tell, the receipts have nothing to do with periodic daily, weekly, and monthly. If you look at the periodic scripts, and there sub scripts, you can see just what they do. They do not reference receipts or boms at all. The do clean logs, update internal databases, and other general maintenance though.

When you install the deltas the processes need to go over the different Receipts and change things several times. Again not accounting for differences you may have unknowingly made between deltas (even trying to fix something yourself).

I am not sure what they change several times. The delta makes a quick read of past receipts, and determines what needs to be done. As the readers of our sitet are new to this, the most they would have messed with is perhaps tossing a pref file. I doubt they would have issues any terminal commands, those being the only thing I can think could possibly mess up a delta update. Largely, I think failures in delta update are due to Apple simply not being able to account for all cases all the time, even though users have not mucked with anything at all. In those cases, the combo updater can in fact save the day, since it does more replacing than patching. My system is heavily modified, and I never user combo udpates, and (crossing fingers) have never had issue.

When you apply a combo you apple a single patch that leaves your disk as if you had just installed the original OSX disk and then applied a single patch. There are no piled-on changes. There are no accumulated user-modifications. There are no conflicting permissions.

A combo is not a patch, Apple’s tech nots explicitly state so. Delta’s are the patches. This is also a pretty broad statement. A combo can only attempt to restore Apple created or endorsed applications and settings. It is very far, in my opinion, from where you would be had you installed OS X, and then ran the combo update. Your statement can be misleading since it made me think that any 3rd party apps I installed would be washed away. There are also some applications that Apple makes that are not updated at all in the combo updater. For example, some of the more obscure apps, such as developer tools, server admin tools etc, are not at all updated by the combo updater.

This is the reason one of the first things Apple Support will do with a glitchy mac is applying a combo update on it.

I do agree, this is a good troubleshooting technique. I often use it for clients. On my own machine, I will tend to want to look at the logs and see why this happened. If I have an issue, and it is caused by some 3rd party app, and then the combo update fixes it, the next time I run the 3rd party app, it could happen again. I tend to want to get to the bottom of the problem, rather than blindly fix it and not know why.

Why “the larger the delta, the better the combo”? Because the larger the delta the more files from the previous delta are touched.

This I would agree with.

Also, keep in mind that a combo update updates any supported mac to the latest version of the OS. If you have more than one mac it’s already worth considering downloading a single updater, putting it on a pendrive and installing in all.

I also always put the latest combo in a partitioned external disk where I’ve loaded the Leopard installer, so I have one quick access to bring a mac up to speed to the latest version of the OS.

Yes, that is a good plan, and if you manage more than 3 or more macs, I think you eventually have to explore this idea. But do remmeber, combo updates, as I mentioned before do not update everything, there are a few, albeit a small amount, of applications that the combo updater does not cover. Some are harder to find in the maze of Apple’s website than it is to just dowload them via software update.

@eduo, thank you for the post, I am sure our users will be able to glean some good data from it. I wanted to clarify a few things. To our users, I would suggest you run Software Update and feel safe in that it is a great way to update your Mac. If you have troubles, by all means try the combo update as a method or repair. Thanks again eduo for posting.

Scott-Thx for your response to my ‘update’ via USB. In the interim, I packed up my rig and downloaded directly onto my computer via a friend’s Hi-speed connection.
Incidentally, my previous attempts at doing same using a USB drive(1GB) had my Mac stating that it needed 225GB to load the 320Kb Combo update! I had 213GB free on the hard drive at the time. I never did figure out the problem. The download using more direct means seems to be working O.K….other than Pages refusing to print, stating that my printer (canon) was ‘offline’. Wiping the printer assignments and reloading the drivers seems to have fixed the problem.
I did notice that my friend’s ‘Hi-speed’ Sympatico connection dropped down to 1/2 dial-up speed after 4:00 p.m. As a result, it took 2 hours to download a 370 Mg update.Shades of things to come? Glad to see you back!
J.P.