* https://klarasystems.com/articles/managing-boot-environments...
* https://wiki.freebsd.org/BootEnvironments
* https://man.freebsd.org/cgi/man.cgi?query=bectl
* https://dan.langille.org/category/open-source/freebsd/bectl/
* https://vermaden.wordpress.com/2022/03/14/zfs-boot-environme...
It lets you patch/upgrade an isolated environment without touching the running bits, reboot into that environment, and if things aren't working well boot back into the last known-good one.
* https://man.freebsd.org/cgi/man.cgi?query=bectl#end
> beadm(1M) originally appeared in Solaris.
* https://man.freebsd.org/cgi/man.cgi?query=beadm#end
Solaris Live Upgrade BEs worked with (mirrored) UFS root:
* https://docs.oracle.com/cd/E18752_01/html/821-1910/chapter-5...
* https://www.filibeto.org/sun/lib/solaris8-docs/_solaris8_2_0...
It allowed/s for migration from UFS to ZFS root:
* https://docs.oracle.com/cd/E23823_01/html/E23801/ggavn.html
It's a bit sad that this Lenovo ThinkCentre ain't using ECC. I use and know ZFS is good but I'd prefer to run it on a machine supporting ECC.
I never tried FreeBSD but I'm reading more and more about it and it looks like although FreeBSD has always had its regular users, there are now quite some people curious about trying it out. For a variety of reasons. The possibility of having ZFS by default and an hypervisor without systemd is a big one for me (I run Proxmox so I'm halfway there but bhyve looks like it'd allow me to be completely systemd free).
I'm running systemd-free VMs and systemd-free containers (long live non-systemd PID ones) so bhyve looks like it could the final piece of the puzzle to be free of Microsoft/Poettering's systemd.