Upgrade mac osx Catalina

I was wondering if i would upgrade to Catalina, would i still be able to run my High Sierra installation without running into issues. Some years ago i upgrades my OS, it also run new firmware. Because of that i could not run my old OS from an external drive.


Thanks in advanced.



Mac Pro, macOS 10.13

Posted on Feb 24, 2020 01:03 AM

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Posted on Feb 24, 2020 07:11 AM


ernstfromhaarlem wrote:

Thanks!

Actual plan is running Catalina on an external SSD through thunderbolt.

This installation would not have any influence on my current high-sierra install?


Correct.

You are installing Catalina on an external drive and your internal drive has High Sierra which will not be touched.

4 replies

Feb 24, 2020 05:19 AM in response to ernstfromhaarlem

You can run both OSs (on separate partitions) if you want without issue. Firmware upgrades that I have encountered running Catalina betas have not cause issues with my day-to-day OS (High Sierra).


If your question is can you upgrade to Catalina then downgrade back to High Sierra without any issues, yes this is possible as long as you have a current back up prior to the upgrade so you can restore.

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Upgrade mac osx Catalina

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