1) Should I Upgrade To This New Major Version Of The Macintosh OS Ever?

1A) Should I Upgrade To This New Major Version Of The Macintosh OS Right Away?

1B) I’ve Skipped Several Versions Of The Macintosh OS.  Should I Upgrade Now?

2) Backup Before Upgrading!

3) Consider Doing A “Clean Install”

4) Before You Upgrade

5) After The Upgrade

6. How To Do A Clean Install Of A Major Version Of The Mac OS

7. Basic Information About Backing Up Your Macintosh’s Data

MacAttorney, the FREE Newsletter for Macintosh Using Attorneys

Upgrading To The Very Latest Macintosh Operating System

                                                        By Randy B. Singer

Copyright © Randy B. Singer, 2018 - 2020. All worldwide rights reserved.
Permission is hereby given to link to this site, but no other use is permitted without express written permission.

Every time a new major version of the Macintosh operating system (Mac OS, or, as Apple calls it, the macOS) is released (e.g. macOS 10.14.0 “Mojave”), the most common questions on Mac users minds are:  “should I upgrade?” and “when should I upgrade?”  There are a number of things to consider in deciding whether or not to upgrade, and when.  And there are some “best practices” to follow to insure that, if worse comes to worst, your data is completely safe and you can get back to where you started quickly and easily.


You won't likely be missing out on any "must-have" features if you don't upgrade your OS for one, two, or even three major versions of the Mac OS. I used to recommend that nearly everyone upgrade to the latest OS once it got to the point-two version (e.g. macOS 10.14.2) and all the most vexing bugs were worked out of it by Apple. Both to have the latest security features and technology, and to be able to run all the latest applications.

But now I realize that many folks are too scared/inexperienced about endeavoring to take upon such a task. It is extremely rare that you will miss out on anything critical by not upgrading. Upgrading is nice, but you usually don't have to do it. And I can't remember a time when there was a version of the macOS that folks wanted badly to leave behind.

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I usually suggest that folks wait for the “point-two: version (e.g. macOS 10.14.2) of a major new version of the macOS before upgrading, for three reasons.  The first is to allow Apple to have enough time to get feedback from users who upgraded right away and to exorcise reported bugs in the new OS.  The second is to allow third party developers who’ve found that their apps broke, or partially broke, under the new OS to get out new versions of their app for you to upgrade to, that work perfectly under the new OS.  Finally, lots of folks don’t like change.  New major versions of the macOS usually include a bunch of changes.  However, given a bit of time, users and software developers usually come up with work-arounds or patches or additions to the new OS that restore things, or functionality that users really miss from previous versions of the macOS.


• I've been recommending that users with internal rotating disk hard drives not upgrade past High Sierra (Mac OS 10.13), because Mojave (Mac OS 10.14) and later non-optionally will reformat your internal rotating disk hard drive to APFS.  APFS is optimized for SSD's, and conversely, because it is not optimized for rotating disk hard drives, it causes a performance hit on rotating disk hard drives.

• I've been recommending that users with a significant number of older 32-bit only applications not upgrade past Mojave since Catalina won't run 32-bit only applications.

If you upgrade past Mojave, you will lose all of your 32-bit only programs.  It could potentially get quite expensive to replace all of your 32-bit software if you have a lot of it.
You can instantly find which programs are 32-bit only on your computer using:

32-Bitcheck (free)
(Check any, or all, folders of your choosing, and you can check just your apps. Generates a text report if you like.)

• I think that it's too soon to upgrade to Big Sur, even if you otherwise think that it might be fine.
Before anyone upgrades to "Big Sur", you might want to listen to this rant:

Big Sur delivers big kick in the balls to Apple users

macOS Big Sur update is bricking some older MacBook Pros

Big Sur 11.0.1 (20B50) has been released and it blocks 2013 & 2014 13" MacBook Pros from installing Big Sur at all.
This move looks to be related to the Big Sur install problems with these models.

Many incompatibilities with applications under Big Sur have been discovered.  See here for a list of applications that no longer work after upgrading to Mojave: 

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Assuming that your older Mac can be upgraded to the latest version of the Mac OS (with each new version of the Mac OS that’s released, some older Mac models are dropped from the compatibility list because their hardware doesn’t meet new requirements), you may or may not want to upgrade to the latest version of the Mac OS.  More recent versions of the Mac OS offer better performance, decreased RAM requirements (Apple has started using advanced memory compression and memory management), increased security, and compatibility with the very latest software.   However, if you will only be holding on to your current Macintosh for another year or less, for instance, you might as well just stick with what you have and upgrade to the latest Mac OS automatically by purchasing a new Mac when the time comes.

The big risk you run by sticking with an older version of the macOS for many years is that technology will pass you by.  Apps get updated, some drastically, and some even disapper.  What you don’t want is to be caught with your data in a file format that is outdated or defunct, with no translators availble to translate things into a modern supported format.  Example:  Many people loved AppleWorks, a multi-purpose app from Apple.  Apple discontinued AppleWorks and lots of Mac users had tons of files in AppleWorks format.  Users who waited too long to upgrade to a new version of the Mac OS, and who thus didn’t immediately look for an alternative to AppleWorks that could import files in AppleWorks formats, found that they had missed the window when alternative apps that could work with a much newer Mac OS included translators for their old AppleWorks files.  For instance, I’m not even sure if you can open AppleWorks drawing files in any modern drawing program once you upgrade.  But for a time, EasyDraw included translators to open AppleWorks drawing files.  There are similar stories for other apps.  Wait too long and technology may pass you by.

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If you are going to upgrade, you really should have a complete backup (or two) of all of your data first for safety. It's rare, but it's not unheard of that something can go sideways during a major OS upgrade. An upgrade can stress your old hard drive enough to make it decide that it's reached the end of its life. Software incompatibilities can bring your computer to its knees. Once again, it's rare, but it happens. Besides, you should have a complete backup that you maintain anyways, if you like your data. A complete up-to-date backup, especially a clone backup, will allow you to quickly get right back to where you started if things go sideways during an upgrade. Heck, even if your Mac just ups and dies, having a backup allows you to continue like nothing happened with a different Mac.

I’m often asked: “I don’t like the new version of the macOS that I’ve upgraded to.  Can I roll back to an earlier version of the macOS?”  The answer is “yes”, but it will only be easy to do so if you did a complete backup of all of your data prior to upgrading.  A clone backup makes it much easier to roll things back than a versioned backup.


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There is no question in my mind that doing a clean install of a major new version of the OS is a much better idea than doing the easier install-in-place upgrade. (An “install-in-place” upgrade is where you install the new version of the Mac OS on top of the older version of the Mac OS that you already have installed.  The Mac’s installer program is left to figure out what goes and what stays.  A “clean install” is where you wipe out your old installation of the Mac OS, and install a completely pristine version of the new version of the Mac OS in its place.) A clean install usually results in a Mac that's noticeably faster, as it precludes the possibility of there being stay-resident software left behind from the old OS version that will cause a software conflict with a resulting stability or performance hit. A clean install is a much more involved process that takes longer, but it doesn't have to be onerous. On this Web page I’ve posted instructions on how to do a clean install fairly easily. If you are going to spend half an hour to 45 minutes upgrading your OS, why not spend a little extra time to ensure a much more satisfactory result?


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Before setting out to upgrade to a major new version of the Mac OS, you should check to see if any of your mission critical applications will need to either be updated or replaced to run with the new OS. If they aren't compatible, and there is no update yet, or no satisfactory replacement, you should wait to upgrade until there is one. There is a nice, free, publicly sourced compatibility database your can check with here:


Likewise, if you have important peripherals that require Macintosh drivers, such as printers, scanners, and mice, you should check the manufacturer’s Web site to see if your model of peripheral needs an updated driver to work with the new OS, and if so, if the updated drivers are available for download yet. If they aren' should wait to upgrade until they are.

You can find the developer’s Macintosh peripheral drivers here:





Fujitsu (ScanSnap scanners)

Logitech (mice and keyboards)

Microsoft (mice and keyboards)

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Keep in mind that the first few days after doing a major OS upgrade that your Mac will be running unusually slowly. This is not because the new OS is intrinsically slow, and it’s not unusual. It's because the new installation of the Mac OS is doing things in the background like indexing the hard drive and caching things. What you should do is set your Mac not to go to sleep, and allow it to run for two or three days 24/7. Once all the background chores are complete, your Mac should fly.

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This is different than what most of the articles on the Web suggest doing. It requires that you have a clone external backup of your internal hard drive. But you should probably have one of those in any case. (If you like your data, and don’t want to risk losing it, it should be backed up.  A clone backup is an exact duplicate of what’s on your Mac’s internal hard drive.  You can even start up from it.  Note that Apple’s Time Machine is not a clone backup.)

- Download the version of the MacOS’s installer program that you want to upgrade to to your startup hard drive (that is, your Mac’s internal hard drive). (It's important to do this first.) The installer program won't show up in your downloads folder, rather it appears in your Applications folder. It will be called e.g. "Install Mojave."  (Note that Apple “Updater” programs, and their “Combo Updater” programs, are not full versions of the macOS, and they are thus not the correct thing to use to do a clean install.   Updater programs update a major version of the macOS from one minor version to another.  e.g. macOS 10.14.0 to macOS 10.14.2.  Both 10.14.0 and 10.14.2 are different versions of Mojave.)

If you need to know what the most recent version of the Mac OS is that will run on your Macintosh, these free applications will tell you:

Mac Profile (free)

MacTracker (free)

Download sources for major versions of the macOS:

OS X 10.11 - El Capitan  FREE

OS X 10.12 - Sierra  FREE

MacOS  10.13 - High Sierra - FREE

MacOS  10.14 - Mojave - FREE

MacOS  10.15 - Catalina - FREE

- Make a bootable clone of your startup drive (that is, make an exactly duplicate of your computer’s internal hard drive on an external hard drive). I use SuperDuper (free/$28) for this:
CarbonCopyCloner ($40)
is also popular. You can even use Disk Utility (installed as part of the Mac OS) to create a clone for free, but it's much slower than SD or CCC.

- If your Computer’s internal drive is the one you use for your work (i.e. for your profession), and you want to be extra careful with your invaluable files, you may want to make a second clone on a second external hard drive, or you may want to make a versioned backup (e.g. Time Machine), or you may want to do a backup to the Cloud, or a combination of these.

- Boot (startup) from your clone (that is, your external drive that you created a clone on). (You can do this by setting your external as your startup disk in System Preferences —> Startup Disk.) MAKE SURE THAT THE CLONE IS PERFECT IN EVERY WAY. Once you are sure that the clone is perfect, use the copy of Disk Utility that resides on your clone to erase your internal hard drive. Make sure that you set things so that your now blank internal hard drive has one partition, uses the GUID partition scheme, and that it is set up as Mac OS Extended (Journaled).
(If you are intalling Mac OS 10.13 (High Sierra) or later, the Macintosh installer program may choose to re-format the disk as APFS.  Don't worry about this; just let the Installer program do it's thing and make that choice.)

- Use the MacOS installer on your clone to install the MacOS on your internal hard drive. During the installation (towards the end), the MacOS installer will ask if you want to move data from another source onto the drive on which you are installing the MacOS. It will give you several options for what you want to move over. Have it move the data you want from your clone onto your internal drive.

That's it. You need to set aside the time to do this. Depending on how much data you need to move over it will take up to a few hours.

BIG TIP NUMBER ONE. Make sure to give your internal hard drive and your external hard drive (and any other hard drives you have connected) very distinct names that make them dead easy to tell apart. Because if at any point in this process you get confused and you designate the wrong drive for a particular action, you will have truly screwed yourself.

BIG TIP NUMBER TWO. The MacOS installer deletes itself after it installs the MacOS. So, if you intend to upgrade several Macs, it's a really good idea to make a copy of the MacOS installer and stash it somewhere before upgrading, because you probably don't want to go through that long download again. A copy in another folder works fine, as will putting a copy on an 8GB or larger USB flash drive.

Some folks like to manually re-install all of their applications as part of a clean install, rather than have them moved over for them by the Installer program or Migration Assistant. Some even insist that it isn't a "clean install" unless you do this. You have to decide for yourself if you feel this is necessary. I don't think that it is, but doing it manually certainly gives you the opportunity to take stock of which applications should be updated for the version of the MacOS you are upgrading to. Once again, here is a database of which apps are compatible with various recent versions of the MacOS:

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There are two basic kinds of backups that you can do of all of your data: a "clone" and a "versioned backup."

A "clone" backup basically creates an exact duplicate of your main hard drive *as of the time of your last backup*. The clone will usually be bootable (that is, you can startup from it), just like the original drive. This type of backup is wonderful to have if you have a catastrophic main hard drive failure, or even if your entire computer is stolen or destroyed. If you have a clone backup all you have to do is designate the hard drive with the clone backup on it as the startup disk in your System Preferences (on any Macintosh computer), and you can go on with your work/life as if nothing happened. (At least as of the date of your last backup. That's why it is important to schedule frequent incremental backups.)

I recommend SuperDuper (free/$28) to make a clone backup:
but some users prefer the very similar program Carbon Copy Cloner ($40):

Time Machine
does what is known as a "versioned" backup. This type of backup is bootable, but it doesn’t get you to your normal Mac OS environment; it’s more like booting up into the Disk Utility program. Instead of creating an exact duplicate of your hard drive, an archive of everything that is now, or ever has been on your drive is created, as of the time of every single past backup. This type of backup is very valuable if you accidentally trash something that you find that you now need, or if you find that you need a previous version of a document that has since been changed.  If your main drive fails, you can still restore it from a versioned backup, but there will be quite a bit more time and work involved than with a clone backup to get things approximately to where they were before your main drive failed, and to be able to get back to work using your Mac. You will also need to purchase another known good hard drive to create the restored drive on.

In my mind, a clone backup is essential. There are ways to get some of the advantages of having a versioned backup without actually having one. One way to prevent trashing stuff and regretting it later (thus obviating much of the need for Time Machine) is to create a new folder on your desktop and call it something like "Pre-Trash." Don't put stuff you want to get rid of in your Trash. Put it in Pre-Trash instead. Inside of the Pre-Trash folder, set the View to By Column and click on the Date Modified header and click on the Date Modified triangle to have the column show the oldest files first. Every now and then you can go into this folder and manually delete files over a certain age. For example, you can delete files that are over three months old...once you are sure that you will absolutely never need them again.

Is there a valuable reason to have a versioned backup in addition to a clone backup?   Yes, a really good one.  If the data on your Mac's hard drive becomes corrupted, or hopelessly infected with malware (of a type that does not yet exist), and your clone backup software runs before you detect the problem...all of your data, both on the source and the backup, will probably be destroyed.  However, if you have a versioned backup, even if it has run subsequent to your data being compromised, you can still completely recover your data using the versioned backup.

When designing a backup plan, it is important to assess what your goals are and to have a plan that is geared towards meeting them.  It is best to have a multi-tiered system, because any single-tiered backup plan can so easily fail.  (I can't tell you how many times I've heard from users who had a complete backup, only to find that, when they needed it, it was corrupted or somehow otherwise unusable.)  I usually recommend a three tiered system, consisting of a clone backup, an entirely separate versioned backup, and a backup only of one's Documents folder each day onto a USB flash drive.  Your backup plan should be based on your budget, the likelihood that you will follow your own plan, the value of your data, etc.

Finally, there is the controversy over backing up to the Web. (That is, using Web-based backup services.) Some folks like doing so because it is inexpensive, and it is off-site.  I fall on the side of being against it, except as a low tier on a multi-tiered backup plan.  There have been lots of stories of security breaches of these services in the news lately, some by our own government, and that is a concern if you have sensitive information.  But mainly I don't recommend Web-based backups because your Internet connection is a huge bottleneck.  Even with a fast cable connection, restoring a full backup from the internet could take over a day, depending on how much data you have backed up.  That's just too much downtime and too much stress on you during what is already a stressful time (having lost a hard drive and needing to restore from a backup.)  However, a Web backup might still be useful as a lower tier in your backup plan, as a failsafe, assuming you aren't concerned about the security issue.

Want to know more about backing up your Macintosh?  Everything that you might ever want to know about backing up your Macintosh is answered in this e-book:

Take Control Of Backing Up Your Mac
216 pages

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Other Web pages by Randy B. Singer that might be of interest to Macintosh users:

• Macintosh Routine Maintenance

• Macintosh Slowdown Solutions

• Macintosh Beachballs!

• Free Or Inexpensive Macintosh Software

• Macintosh Accounting Software

• Macintosh Email Software

• Macintosh Word Processing Software

• The List of Law Office Software for the Macintosh Computer

If you have any additions to this Web site to suggest
I would very much appreciate hearing your suggestions.
Send them to:
Randy B. Singer

About The Author Of This Web Site:

Randy B. Singer is:

- The head of the MacAttorney User Group
with, at this writing, close to 10,000 members!

- A co-author of The Macintosh Bible (4th, 5th and 6th editions);

- Author of the ABA publication:
The Macintosh Software Guide for the Law Office

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