Trying to install Sequoia for Dual Boot with Tahoe.

kenfrompershore wrote:

I have a 2019 MacBook Pro running Tahoe. I now want to Dual Boot this with Sequoia. I have created an AFPS container and named it MACOS Sequoia & downloaded Sequoia. When I click on the installer I get a pop up that says. 'This installer cannot be used from the version of macOS you are running'. How do I install it?

Container is basically a Partition ?

I suspect adding a Volume instead of a Container...

Note: you can add a volume within the original container without penalty.

ref: Add, delete, or erase APFS volumes in Disk Utility on Mac

You can create a Bootable USB installer to install the OS there on your newly selected Volume

Create a bootable installer for macOS

when you boot up holding the Option key you can select the start up volume..

or the >System Settings>Startup Disk to choose a default

ref: Use more than one version of macOS on Mac - Apple Support

You need to use a bootable USB installer. Apple doesn’t recommend running long-term dual boot on two volumes in the same container, but I’m not sure how a separate container would affect that.

Create a bootable installer for macOS - Apple Support

For the bootable installer, you’ll have to enable external boot in the security set up, utility in recovery.

Your Mac is currently running Tahoe so the “Install macOS Sequoia” application installer that you are clicking in your Applications folder cannot be run.

Follow the guidance provided by both @leroydouglas and @Barney-15E and create a bootable USB installer on a flash drive. Then reboot your Mac from that to proceed.

kenfrompershore wrote:

1. In the sidebar, select your existing APFS volume, such as Macintosh HD.

I'm not sure which one I should choose to add my new volume too.

There is Macintosh HD Volume Group, Macintosh HD System Volume ( Greyed out), Macintosh HD Startup Snapshot & MacIntosh HD Data.

If I select the first one and create a MACOS Sequoia volume, I get the same message 'This installer cannot be used from the version of macOS you are running'.

None of those are Containers. They are all volumes in the same container. You need to select Show all devices from the View popup menu. You then select the enclosing container and add a volume there. If you had a volume selected and you were able to “Add Volume,” I would suppose it would be created in the same container.

regardless, you will never get anywhere unless you startup from a Bootable USB Installer.

Plus you will need to first modify the laptop's security settings by allowing "booting from USB" by using the Startup Security Utility so you can boot from the macOS Sequoia USB installer:

About Startup Security Utility on a Mac with the Apple T2 Security Chip - Apple Support

Edit: How much Free storage space do you have on your SSD? You need at least 80GB+ of Free storage space just to install another OS. You need to make sure you always maintain at least 20GB+ of Free space, but you likely need to have a lot more Free storage if you want to do anything significant with either OS.

FYI, ignore the "Available" storage space shown everywhere in macOS since it is very misleading. Within macOS "Available" is not synonymous with Free. Plus the only locations which report the actual Free storage space is within Disk Utility and the System Profiler.

I would strongly suggest not running a Dual Boot Tahoe and Sequoia, for other reasons

Have worked with at least one individual who had endless issues with the Touch ID functionality when dual booting Tahoe and Ventura

Firmware Compatibility and Secure Enclave Risks

Be aware that macOS 26 (Tahoe) likely include a firmware update affecting the logic board and Secure Enclave ProcessorSEP).

Running a dual boot setup (e.g., Sequoia) may introduce firmware mismatch issues, leading to instability or loss of functionality.

There have been at least three documented cases where downgrading a or possible Dual Booting from Tahoe to Sequoia resulted in Secure Enclave malfunctions, requiring full system restoration or hardware servicing.

Proceed with an abundance of caution and or a Recovery Plan should it been needed

eg Access to another Apple computer currently running macOS 15 or macOS 26 (Tahoe).

This secondary system must be capable of performing a Revive or Restore operation on the target Mac’s firmware if required.

Lack of a secondary Mac significantly reduces the ability to recover from firmware corruption or boot failures.

Firmware Compatibility and Secure Enclave Risks

They don’t allow you to run older mac os installers from newer versions because it would allow anyone to downgrade their mac to much older versions. You can also not dual boot mac os because of the firmware differences. Though because you have an intel mac you could dual boot windows or linux because they will just use the same firmware as mac os without changing it.

Duder967 wrote:

1 - They don’t allow you to run older mac os installers from newer versions because it would allow anyone to downgrade their mac to much older versions. 2 - You can also not dual boot mac os because of the firmware differences. 3 - Though because you have an intel mac you could dual boot windows or linux because they will just use the same firmware as mac os without changing it.

1 - Factually incorrect 

To downgrade would require erasing the whole drive First and then install from a Bootable Installer 

2 - Factually incorrect 

It can be done, though with certain Risk Factors as already mentioned 

3 - Yes,  Windows 10 is supported when using Bootcamp. 

Linux - maybe. Provided the drive has enough Free Space and also allowing the Linux installation to make a new ext4 Partition

I have tried to dual boot Mac OS before and only ended up bricking the Mac. and you can run older installers but not without entering recovery mode first. you can not run the gui usb creator from a newer version but you can use the command line to make the usb installer. And while windows 10 is natively supported windows 11 can be made to work. and Ubuntu linux generally works out of the box with Intel Macs

Duder967 wrote:

I have tried to dual boot Mac OS before and only ended up bricking the Mac.

Unless you are running a hacked macOS (either acquired from a source other than Apple with "malware" or one made to be used on an unsupported Mac), then something else is going on. Yes, you can get some Macs into a state where they may not respond & it can be difficult to figure out why, but they are rarely bricked unless it has a latent hardware failure.

The only time I've seen a macOS installer actually & literally brick a Mac was with the original Monterey installer bricking 2014 MBPros (Apple pulled it for a while) and I have seen a third party OS brick a Mac as well due to bugs in Apple's firmware while configuring the PRAM for setting the default startup drive (that firmware was flaky anyway). A Mac may become bricked from macOS if the Mac has an issue during a firmware update like a power outage or is powered off during the process....this is always bad news no matter what the device as it is not an Apple specific issue (years ago Apple actually had firmware restoration CDs for those occasions, but not any more).

and Ubuntu linux generally works out of the box with Intel Macs

With older 2007 to 2015 non-USB-C Macs, yes. Ubuntu currently is unable to support some aspects of the USB-C Intel Macs, especially the T2 models although some updates may be coming soon for supporting the Touchbar.

Owl-53 wrote:

Duder967 wrote:

2 - You can also not dual boot mac os because of the firmware differences.

2 - Factually incorrect 

It can be done, though with certain Risk Factors as already mentioned 

FYI, With the M-series Mac, things are a bit more complicated. I thought I understood one aspect, but encountered something recently which has me believing I was wrong about how the dual booting works on an M-series Mac. Dual booting a T2 Intel Mac may also have some complications due to the T2 security chip (it even has issues with multiple user accounts with a single OS...lots of bugs experienced first hand).

Otherwise dual booting with an older OS isn't much different than downgrading the OS. The system firmware is the same regardless and in many cases the older OS will have likely updated the system firmware to the same as is used by the next major version of macOS. Once the system firmware is updated, Apple does not downgrade it. Again, the M-series Macs may be a bit different, but the OP here is on an Intel Mac where that is generally the rule.

Duder967 wrote:

I have tried to dual boot Mac OS before and only ended up bricking the Mac.

Lesson learnt

Proceed at your own risk