#Using external ssd as boot drive mac install
#Using external ssd as boot drive mac update
#Using external ssd as boot drive mac pro
#Using external ssd as boot drive mac mac

This therefore appears to be a bug in current Big Sur installers, which donвЂ™t work reliably with some (if not most) external disks connected via USB-C rather than Thunderbolt.

#Using external ssd as boot drive mac mac

Installing macOS 11.1 on that external disk appeared to proceed identically until the installer reached the final minute, where it took much longer than the Thunderbolt disk had done.Д®ventually, the installation completed, but the M1 Mac restarted from its internal disk, complaining that the external disk couldnвЂ™t be used for booting. If you try to use the Startup Disk pane to restart an Intel Mac from an M1 bootable external disk, all that happens is that your Mac restarts from its internal disk and ignores your setting.Д«uoyed by this success with an expensive Thunderbolt 3 SSD, I thought I might finally succeed in booting my M1 Mac mini from a much cheaper Samsung 860 EVO SSD in a USB-C enclosure. I suspect that this involves updating the hidden EFI partition, although curiously the Intel Mac saw my bootable disk with the name EFI in the first place. When I tried to start up from mine from Intel Recovery mode, macOS wanted to perform a вЂњsoftware updateвЂќ before that might become possible. Your bootable external disk now works with other M1 Macs, but not, as it stands, with Intel Macs. In the end, I just disconnected the disk, and no howls of anguish came from the Mac. Unfortunately, on an M1 Mac running macOS 11.1, the Data volume is usually left behind, and any attempt to eject it will result in your being told that itвЂ™s still in use, while trying to open the volume denies that itвЂ™s present at all. Oddly, on Intel Macs running Big Sur, the Data volume isnвЂ™t shown as a separate volume, but on M1 Macs it is. Clicking on the Eject tool for the System disk brings a helpful dialog which offers to unmount both System and Data volumes. Once booted from the internal disk again, ejecting the bootable external disk isnвЂ™t fault-free. Your M1 Mac will then restart from the selected disk.

In the first screen displayed there, rather than select the Options item to proceed to Recovery, select the disk which you want to boot from and click Continue underneath it. Its new equivalent is in the opening of Recovery Mode. M1 Macs lack the old Startup Manager, and holding the Option key during startup does nothing at all. When you want to restart from the internal disk, the Startup Disk pane is your best option. YouвЂ™ll have to go through the whole process of setting your AppleID to work, negotiating two-factor authentication for this вЂnew MacвЂ™, and so on, until you can finally use your external disk fully. With AppleID and current setups, what you now effectively have is not simply another boot disk, but a whole new Mac bar the hardware. This should be relatively rapid, and at the end your Mac will automatically restart into the freshly installed copy of Big Sur on your external disk. Then select the external disk and click Continue.ДЇollow the installation process through to completion.

#Using external ssd as boot drive mac install

When it invites you to select the disk on which you want to install Big Sur, if you donвЂ™t see your external disk, click on the button to show all available disks. Then open the Install macOS Big Sur app, and proceed.

#Using external ssd as boot drive mac update

a copy of the Big Sur 11.1 (or later) installer app, obtained from the App Store via Software Update this procedure appears less reliable in macOS 11.0.1 and when installing macOS 11.0.1, so 11.1 is recommended for both.Д¬onnect your external disk, and if thereвЂ™s any doubt about whether it has been freshly formatted using APFS without encryption, use Disk Utility to do so before going any further.

#Using external ssd as boot drive mac pro

Some suggest that if your SSD isnвЂ™t Thunderbolt, try connecting it via a USB-A port, although that doesnвЂ™t help those with MacBook Air or Pro models

a Thunderbolt 3 SSD, such as a Samsung X5, freshly formatted in APFS (unencrypted) and connected to one of your M1 MacвЂ™s Thunderbolt ports if you only have SATA SSDs which connect via USB-C rather than Thunderbolt, you may be successful, but it seems unlikely.

an M1 Mac if you havenвЂ™t got one yet, IвЂ™m afraid itвЂ™s far too late for Christmas.

Thanks to many comments but no real clues, IвЂ™ve now been able to solve this, and here explain how you can do this too. Last week I described how I had been unable to get either of my M1 Macs to start up from an external disk.