I get continuous reboot after 15.0 upgrade

[Carl Johnson]

I was just tring to upgrade from 14.3-RELEASE-p6 to 15.0-RELEASE, but I
am just getting continuous reboots now. The system is an amd64 based
system running with zfs on root. I first upgraded to 14.3-RELEASE-p7 as
directed, and then did the upgrade to 15.0-RELEASE. I didn't see any
errors and everything seemed fine until I rebooted. I don't see any
unusual messages in the startup, but then it reboots after saying that
it is starting local daemons. Since I have zfs on root, I was able to
boot from a 14.3-RELEASE-p7 boot environment, but I can't run 15.0.

Does anybody have any suggestions on how to debug this since I don't see
anything useful in the log files?
--
Carl Johnson ca...@peak.org

[Daniel Tameling]

Boot the system in single user mode, mount the filesystem writable and
comment out everything unnecessary in /etc/rc.conf. Same for @reboot
items in your crontab and unnecessary filesystems in /etc/fstab. Then
try booting again. If it works, you can slowly reverse what you did to
find the culprit. If it still doesn't boot, you have got a real
problem.

Best regards,
Daniel

[Carl Johnson]

Thanks for the suggestions, but it will probably be a couple of days
before I try that again. Unfortunately, I will have to start again
since I removed the BE that wouldn't boot up. I had tested that it
would boot up in single user mode, but I had only tried removing a
couple of things from /etc/rc.conf. I will try your suggestions before
I try the next time.

Thanks for your help.
--
Carl Johnson ca...@peak.org

[Gerard E. Seibert]

On Tue, 27 Jan 2026 08:56:22 -0800, Carl Johnson stated

I experienced a comparable issue and determined that the following
method was effective.

To address spontaneous reboots, boot into single-user mode, mount the
system, and rename the rc.conf file. Rename the rc.conf file to
rc.conf-bak and reboot the system. If the system remains stable, the
issue likely originates from that file. Restore rc.conf-bak to rc.conf,
then comment out each line in the file. Review rc.conf systematically,
enabling one service or option at a time and rebooting after each
change. Although this process may be time-consuming, identifying the
cause will facilitate a straightforward resolution.

Good Luck!

--
Jerry

[Carl Johnson]

I haven't gotten around to it yet, but that looks like a good way to go.

[fatty.merc...@aceecat.org]

On Thu, Jan 29, 2026 at 10:18:22AM -0500, Gerard E. Seibert wrote:

> To address spontaneous reboots, boot into single-user mode, mount
> the system, and rename the rc.conf file. Rename the rc.conf file to
> rc.conf-bak and reboot the system. If the system remains stable, the
> issue likely originates from that file. Restore rc.conf-bak to
> rc.conf, then comment out each line in the file. Review rc.conf
> systematically, enabling one service or option at a time and
> rebooting after each change. Although this process may be
> time-consuming, identifying the cause will facilitate a
> straightforward resolution.

An improvement on "one option at a time" may be some form of binary
search. You probably need a specific way of commenting out to keep
track where you are in the binary tree.

--
Ian

[Carl Johnson]

I finally got around to it and got it down to the 'kld_list' line. It
turns out that 'kldload amdgpu' will cause instant system panic. I
tried radeonkms and it doesn't cause a system panic, but it won't allow
X11 to work. I have shelved that boot environment and gone back to my
14.3 version.

Thanks for the suggestions and help.
--
Carl Johnson ca...@peak.org