Why did I need to restart to upgrade my recovery partition?
I tried to upgrade my recovery partition today and it failed with "No such device"/OS error 19.
I found this discussion on Reddit in which @mmstick suggested restarting, but with no explanation as to why that was needed or would work. It worked for me.
I'd like to know why it worked and why it was needed, mostly for two reasons: to generally understand the situation better and to imagine what I might have been able to do that didn't require restarting.
Standard IT practice to turn it off and on again. Some updates require system restarts to apply the update to the running system, otherwise you may see some broken behavior where something's inaccessible because the installed drivers don't match the kernel you're using.
I have also upgraded the recovery partition on this machine every 3 months for over 3 years before needing to reboot to make it work this time. I'm curious what might account for the difference.
Also, I'm not sure how upgrading a recovery partition constitutes updating a running system. I had not booted from the recovery partition. I was not running anything from the recovery partition.
Yes, it was. I checked by unmounting it, then running the upgrade command, which resulted in a clear error message about the partition not being mounted. I don't remember the specific message, but I remember it was different than the one I got when it was mounted. This leads me to believe that the OS error 19 message is some kind of red herring.