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How often do you clean install macOS?

Rychiar said:
typically when I buy a new computer just to clean out some junk data
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For a Mac, wouldn’t that be exactly when you’d least need to restore to factory settings, since it just came from the factory?
 
Nermal said:
My argument is that deleting and reinstalling the same data is equivalent to leaving it there.
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I'm sure this is how it's meant to work. I just don't trust the Mac OS to do a full clean up during the "Erase All Content and Settings" operation.

Knowing that tens of thousands of files accumulate in the Mac OS over years, I just don't see how they all can be erased perfectly. I don't see Mac OS restoring all changed files to their original versions either. If I were to build that feature, I would literally just erase all user content and settings, and maybe I'd do a very basic Mac OS clean-up too. But I wouldn't be meticulously searching for every little file that shouldn't be there or every file that's changed.

I understand full formatting of the SSD. This leaves no doubt that it's all been cleaned up :)
 
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Andrey84 said:
Knowing that tens of thousands of files accumulate in the Mac OS over years, I just don't see how they all can be erased perfectly.
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macOS is now installed inside a sealed volume. So any junk files like you mentioned would not be in the sealed OS volume, they are all in the Data volume, which is wiped when you do the erase setting routine on newer Macs. So the erase settings has the same end result as a format and reinstall.
 
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2004 iBook > 2008 aluminum MacBook > 2012 MBP > 2015 MBP > 2018 MBP, first clean laptop install.

2004 iMac > 2009 Mini > 2010 Mini > 2012 Mini > 2014 Mini > 2013 Mac Pro trashcan > 2019 iMac, first clean desktop install.

2018 Mac mini; headless media server outlier... So, every 15 years or so?!
 
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Weaselboy said:
macOS is now installed inside a sealed volume. So any junk files like you mentioned would not be in the sealed OS volume, they are all in the Data volume, which is wiped when you do the erase setting routine on newer Macs. So the erase settings has the same end result as a format and reinstall.
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Ok great, thanks.

It looks like they fixed their problem with Mac OS becoming corrupted since the Big Sur and I don't need to do clean installs anymore.

eclecticlight.co

How macOS is more reliable, and doesn’t need reinstalling

How APFS, the boot volume group, hashes, and Secure Boot all combine to guarantee the integrity of your system, and save you trouble and work.
eclecticlight.co eclecticlight.co

Signed system volume security

SSV not only helps prevent tampering with any Apple software that’s part of the operating system, it also makes macOS software updates more reliable and much safer.
support.apple.com
 
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Andrey84 said:
Have you run out of money in 2020? 😉
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Haha - I appreciate a solid zing. I should say yes. 🤣

No, the reality is all of those computers were bought when they turned 3 years old on average. Many from here, actually, the rest from eBay.

Settled into a computer for a few years until it got slow or I ran out of space. Then they went on to their next homes.

Outlier in that list I totally forgot was a trashcan Mac Pro destined for the bin when it was 6 years old. Saved from scrap she was! Destined to become an art piece after the MBA, next to a similarly-discarded predeceased G4 Cube.

I should close, back on topic, I used the trashcan simply because I got a 1TB blade for it and I wanted the course work space. I sailed past 500gb. When I deleted some unnecessary crap, and allowed macOS to nuke the leftover bits of 3 versions of Office (and more I’m sure), I gained north of 200gb back. I now barely crack 300gb on the only Mac with my content on it. Those leftover bits (the system data category) can certainly inflate if unchecked.
 
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Ben J. said:
A clean install might still be a good thing to do, sometimes.

I quote myself from this thread:



Yes, the SSV system volume is completely rewritten on any upgrade, but you might have old software, maybe outdated kernel extentions that might be problematic, and they continue to stay on the '- data' volume unless you do a clean install and start from scratch. Migration Assistant will also keep old, possibly problematic stuff.
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If you know where macOS stores things and are diligent about removing things that are installed after the uninstaller forgets to or otherwise doesn't do it.... macOS can be kept quite clean pretty easily.

A couple of caveats for me not reinstalling macOS:
  • if you use home-brew and change from intel to Apple Silicon - remove and reinstall home-brew. Otherwise you'll be running stuff in Rosetta.
  • I run with gatekeeper on and everything I can install from the App Store is downloaded from the App Store. I'm pretty strict about trying to keep trash software off my machine in the first place
But as above, macOS now has a read only system partition so the need to reinstall the OS is basically not a thing any more, particularly if you keen an eye on the Library folders for left over trash when removing an app.

My current macOS install has been ported from machine to machine via Time Machine or machine to machine transfer wizard since my 2015 MacBook Pro. I've never done erase content and settings.
 
Eriamjh1138@DAN said:
Haven’t done it in 22 years. I still have remnants of 2002 PPC G4 apps I can’t run on my machine. Been migrating ever since.

I’m getting a mini M4. I’ll start from scratch for the first time in a long time.
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Lol, given preferences come across you could be in for a bit of a shock with the defaults that have changed since 22 years ago :D
 
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I think the last time I did an erase and install was my G5 Cheesegrater Mac. The original MacPro was my next Mac and it just seems like every major OS upgrade since then has come at a time when I flat-out didn't have time to mess with restoring data and installing apps. Thing is, I've not had any issues doing plain old upgrades instead of clean installs.
 
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Eriamjh1138@DAN said:
Haven’t done it in 22 years. I still have remnants of 2002 PPC G4 apps I can’t run on my machine. Been migrating ever since.

I’m getting a mini M4. I’ll start from scratch for the first time in a long time.
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Amazing! This is EXACTLY my situation today! I assume I shouldn't bring over apps, but how do I migrate over all my preferences and settings without bringing the junk? Will migrating my whole User folder junk up my new M4? Thanks for any answers! Btw, I'm running...

My Mini 2018.png
 
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I did a clean install this time, and let me just say - having screen time turn on by default and lock me out of my gaming session 1/2 an hour into it after a long day was a pain in the butt.

I've never messed with screen time before, its taken me a couple of goes to turn it fully off!
 
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