various questions about booting and recovery

[Polytropon]

On Sun, 4 Jun 2017 13:02:59 -0400, Littlefield, Tyler wrote:
> My biggest problem is that I always end up somehow breaking things and
> then need to get eyeballs (I'm totally blind) to help me
> recover/reinstall. Both systems are using zfs. I've tried to figure out
> the multiboot environment, but not having much luck. I can force my
> systme to reboot, but I'm curious if there's an easy way to set up
> multiboot environments so I can boot configurations to test. If so, are
> there some clear instructions somewhere on how to do so?

Given that you're already using ZFS, Boot Environments (BEs)
seems to be what you are looking for. There is a tool to
easily do the "housekeeping", like creating snapshots, editing
the boot attribues, and switching what to boot: beadm.

Here are a few resources that will help you discover BEs:

Manual page for beadm:

https://www.freebsd.org/cgi/man.cgi?beadm

HOWTO for beadm:

https://github.com/vermaden/beadm/blob/master/HOWTO.htm

How To Use beadm to Upgrade FreeBSD installed in a ZFS Boot Environment,
with minimal downtime:

https://www.dweimer.net/?Content=03~help_files&Page=02~beadm_and_FreeBSD_on_ZFS



> Finally, can I have it boot to an environment once and if it reboots
> swap back to the old one?

Yes, that's the exact purpose of ZFS+BEs in a nutshell. ;-)


-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...