Best way of reinstalling Mac OS?

[Orange Cola]

I’ve just updated my ‘Late 2012 iMac’ which I bought in 2013 to macOS Catalina. A few symptoms cropped up, beach ball of death at pretty much every click, finder, about this Mac etc. And a 3-4 minute boot time.

I’ve done some internet research which has lead me to carrying out some general house tidying and cache clearing but I’m only just down to sub 2 minute boots and there’s been an improvement in hanging time but not I’m far from fixing it.

I’ve never reinstalled the OS but I’ve always taken the latest updates so reading around I think I just need to reinstall the OS.

It seems there’s conflicting information on how to do this, according to the Apple website I think I can reinstall from a time machine back up however the other reputable Mac sources of information say I need to reinstall the OS then install from a time machine back up to be completely clean.

Any ideas?

[Matty]

I'm not 100% on a TM backup, but if its a full warts-and-all backup and restore, then more than likely you'll end up just restoring whatever it is that's causing the slow performance.

I'd say you'd be best off taking a full backup, doing a complete clean/fresh wipe from the recovery partition then just recovering the specific files + data you want back so it's nice and clean.

[Orange Cola]

That’s what I’ve just been mulling over, as Time Machine is effectively a disc image I might end up wasting a number of hours changing precisely nothing

[Mito Man]

Could just be too old to run it smoothly. I had the same with my late 2012 Mac mini when updating to High Sierra and fixed it by adding an additional 12gb of ram.

[Orange Cola]

Could just be too old to run it smoothly. I had the same with my late 2012 Mac mini when updating to High Sierra and fixed it by adding an additional 12gb of ram.

Mines a 21.5” iMac so not easy to change the RAM myself The system stats are showing it hanging with virtually no CPU or RAM usage though, clearing the RAM on boot made a difference though.

[Mito Man]

Hopefully the reinstall fixes it but I don’t update my old MacBooks after a few years for the same reason! They just grind to a halt...

[Orange Cola]

Hopefully the reinstall fixes it but I don’t update my old MacBooks after a few years for the same reason! They just grind to a halt...

I guess I could roll it back on time machine...

[IanF]

I’ve a gen 1 retina MacBook Pro (mid ‘12?) and it’s on the latest OS build, plus I’ve taken it apart for a trackpad replacement , and it works fine. I don’t think it’s an OS/hardware issue, just an install problem. Have you run diagnostics? Always fixes any issues I have.

[Nathan]

Internet Recovery or create a USB install thumb drive

[Orange Cola]

I’ve a gen 1 retina MacBook Pro (mid ‘12?) and it’s on the latest OS build, plus I’ve taken it apart for a trackpad replacement , and it works fine. I don’t think it’s an OS/hardware issue, just an install problem. Have you run diagnostics? Always fixes any issues I have.

I’ve run the health check option on the disc repair, that did make a difference in bringing the boot times and beach ball of death occurrences down. I think it’s an install problem too, google seems to suggest the Beta version suffered a lot of boot and hanging issues and they haven’t been fixed in the formal release however it’s been getting slower for a while now and this hasn’t just tipped it over the edge but gone well beyond that.

[Orange Cola]

Internet Recovery or create a USB install thumb drive

Yep, but after I’ve done all that will I reintroduce the problem if I do a restore from time machine?

[Mr Pish]

Internet Recovery or create a USB install thumb drive

Yep, but after I’ve done all that will I reintroduce the problem if I do a restore from time machine?

Quite possibly

I would backup the data you want to cloud or usb if you can and then clean install the highest supported OSX from USB

I find onyx can clear a few issues with OSX

https://www.titanium-software.fr/en/onyx.html

[Ascender]

If its not too much of a pain, I'd do what Nathan suggests - a clean install and then load stuff back on manually rather than restoring from Time Machine.

Which is a bit of a PITA, but hopefully not too much of one assuming data is in the cloud and you can restore some stuff from the TM backup? Even if you do one thing at a time once you've got the system up and running.