Safe to dual boot High Sierra and Big Sur?

[theorist9]

I'm currently dual-booting High Sierra and Catalina on a 2014 MacBook Pro without issues. High Sierra is my primary OS; I use Catalina for programs that will no longer run on HS (e.g., Turbo Tax).

I'm thinking of upgrading the Catalina partition to Big Sur. Will this cause problems?

I've read that dual-booting High Sierra and Big Sur can be problematic. I certainly don't want this to happen:

Startup disk of High Sierra disappeared a… - Apple Community

discussions.apple.com

[This wouldn't be catastrophic for me, since I have multiple backups, but still...]

It looks like you need to be sure to install Big Sur in a separate container (i.e., a separate partition), not merely a separate volume in the same container. That seems to be the issue with the above—the poster had both Big Sur and High Sierra in different volumes in the same container. Fortunately, my Catalina install is in a separate container, so whatever I do in upgrading to Big Sur, it seems it should be completely insulated from my High Sierra install.

https://www.reddit.com/r/hackintosh/comments/jun2n2

 

[KeesMacPro]

Generally it's not recommended to install different OS on the same physical disk.
In case the disk fails, both OS and all data will be gone .

The other thing is the way the OS manages APFS containers.
This changed with BS.

To save yourself from a lot of headaches , I would install BS on another disk.
For a MBP this would mean to remove the DVD drive and buy an adapter to install a 2nd disk where the DVD drive was,
or keep the BS disk external at least for testing first.
TBH I havent tested BS in dual boot setup, but from what i've read this might not work....

 

[theorist9]

Generally it's not recommended to install different OS on the same physical disk.
...

That's not correct. It is not generally the case dual-booting is not recommended. It's in fact quite the opposite: MacOS is designed to allow for dual-booting. Bootcamp is an example. See also this from Apple about dual-booting different OS's: https://support.apple.com/en-us/HT208891

In case the disk fails, both OS and all data will be gone .

That's not an argument against dual-booting, that's an argument for having a backup. If the disk fails, you're going to lose your data regardless of whether you are single-booting or dual-booting

For a MBP this would mean to remove the DVD drive and buy an adapter to install a 2nd disk where the DVD drive was,
or keep the BS disk external at least for testing first.

You're thinking of very old MBP's; it's been nearly a decade since the last MBP's with DVD's were released.

TBH I havent tested BS in dual boot setup, but from what i've read this might not work....

Reference?

 

[KeesMacPro]

It is not generally the case dual-booting is not recommended. It's in fact quite the opposite: MacOS is designed to allow for dual-booting. Bootcamp is an example. See also this from Apple about dual-booting different OS's:

You could re-read the frase :Generally it's not recommended to install different OS on the same physical disk.

That's not an argument against dual-booting, that's an argument for having a backup. If the disk fails, you're going to lose your data regardless of whether you are single-booting or dual-booting

Obviously, in case of 2 OS on 1 disk you'll lose 2x data + no working OS

You're thinking of very old MBP's; it's been nearly a decade since the last MBP's with DVD's were released.

Well, according to your 1st post , your MBP is from 2014. I'm writing this on a MBP2012 that had a DVD.

Reference?

Dont mention it, my pleasure.

 

[theorist9]

You could re-read the frase :Generally it's not recommended to install different OS on the same physical disk.

What I referenced specifically refers to dual-booting on the same physical disk.

With all due respect, here's the problem: Everything you wrote in your original response is either inapplicable or flat-out wrong. Fortunately, I know enough to recognize this. But others who ask for help here may not, and thus won't realize they're being misled. Thus I would urge you to not post about subjects you simply don't understand.

 

[KeesMacPro]

Fair enough,
TBH i'm no MBP expert that knows the specs of every MBP from the last decade.
"inapplicable"? there's USB and Thunderbolt to connect an external drive to test it first.

Anyway, why ask if you seem to know how to do it and the possible risks?
Go for it.

 

[theorist9]

To answer your question: I'm asking because, while I know that dual-booting different OS's on the same physical disk is generally fine (especially if they're on separate partitions—I'm currently dual-booting High Sierra + Catalina, no problem), I wanted to know if there might be unusual issues specific to dual-booting High Sierra + Big Sur of which I might be unaware.

 

[KeesMacPro]

My question was rhetorical.

while I know that dual-booting different OS's on the same physical disk is generally fine (especially if they're on separate partitions

I would remove the word "especially" .
There is no other way than by making separate partitions.
Could be misleading.

 

[JaSuS]

anyone has an idea how to truly disable SIP in Big Sur? I've been trying to install Boom 3D but SIP would not give permission to use microphone...I tried csrutil disable via the recovery mode of Mac OS to no avail.

 

[avz]

I don’t see any issues but I would definitely partition the drive first so each macOS has its own APFS container instead of just a volume under one container for both.
As far as I know having different partitions is like having two different Macs.

 

[Rimmsi]

Hi, so as not to start an unnecessarily new topic, I will ask here. Is it possible to run Sierra and Monterey dual boot without problems? Thanks.

 

[Mustard Seed]

If both High Sierra and Big Sur on separate bootable partitions, does that mean that applications need to be installed on both partitions as well? Especially if different versions of the same app are compatible with HS and BS?