1. From what I have experience and read elsewhere creating a bootable external drive on an M1 Mac is tricky. Even a different model SSD from the same manufacturer can make a difference. The combination I know that works is a Samsung X5 512GB Thunderbolt 3 SSD, directly connected to either of the Thunderbolt 4 ports on an M1 Mac, and using a bootable flash drive installer. (Instructions for creating a bootable installer here.
  2. No other combination of connecting ports, drives, etc. I tried either completed the installation process or subsequently failed to boot with an error 104. ๐Ÿคฌ
  3. If you have stored your data, Documents, Desktop, etc. on iCloud recovery is a piece of cake ๐ŸŽ‚, simply log into your iCloud account in System Preferences and have a network connection.
  4. Recovery from TM or another System drive is a total PITA ๐Ÿฅต because all of the various security settings have to be reset, drivers and some apps must be reinstalled, etc. (did I mention all the ๐Ÿคฌ security settings have to be reset.) NOTE: Migration Assistant will not migrate data from a newer OS version like macOS 11.2 to an older macOS installation like macOS 11.1. (If only Apple would get the ASR utility to work on M1 Macs so they could be cloned. I am becoming a convert to cloning. ๐Ÿฅบ)
  5. Speaking of cloning, I have yet to get Mike Bombich's suggestion of how to create a bootable clone to work, but I am still trying. I suspect that like creating a bootable external drive on M1 Macs it is a matter of figuring out the right configuration, devices, and holding your mouth right and resetting all the ๐Ÿคฌ security settings.


During all of the installs, reinstalls, recoveries, etc. I noticed a new to me feature in Time Machine. Previously if you wanted to encrypt Time Machine backups that was done by backing up to a previously encrypted drive. I don't know when this changed, but in Big Sur the option has been added to the Time Machine pane in System Preferences "Encrypt backup" which does exactly that, it encrypts your Time Machine backup(s). The downside is that it must erase the drive in order to setup encrypted backups. The upside is it works rapidly and seamlessly using a very secure encryption algorithm.

Last edited by joemikeb; 01/14/21 08:41 PM. Reason: Add link to bootable installer instructions

Make intentional errors โ€”
Otherwise the Great Spirit realizes you have fulfilled your purpose on earth.

โ€” Navajo saying