Boot hangs in single-user mode

[Andrew Hamilton-Wright]

Hi Everyone,

On Thu, 6 Jun 2013 10:24:52 -0300, Andrew Hamilton-Wright wrote:
> 
> Strangely, it seems that I cannot boot single user, either
> using "boot -s" from the boot loader, or using the boot menu. 
> When I get to the point where the root filesystem is mounted,
> it hangs right after printing the message:
> Trying to mount root from ufs:/dev/ada0s1a


There was a bit of a delay getting back to this, as I needed to move the internals over to a replacement server in a planned upgrade.

I have left the boot disk in the machine demonstrating this problem with the intention of coming back to determine what is going on (mount points to now-missing data disks have been removed from /etc/fstab).

In the resulting stripped down system, I have the same behaviour as before -- I cannot get to single-user mode, but multi-user is fine.

If in multi-user mode, if I issue "kill -TERM 1" to go to single-user mode, I would get a single console message:  "pflog0:  promiscuous mode disabled", then nothing.  While I would expect pflog to shut down in this case, I have now disabled everything pf related (I cannot imagine that it would interfere with console operation), and now have the situation where kill -TERM 1 simply locks the console.

Plugging in a USB device while the console is locked does produce the expected dmesg updates, and the system does respond to [CTRL]-[ALT]-[DEL]


I will also add that I can boot to a single-user prompt when booting off of the 9.1 media via DVD and mounting the root filesystem from the disk.  (This motherboard+kernel have never gotten along particularly well with the DVD reader/writer in the machine, so mounting the filesystem from the DVD usually fails with various atapi based timeouts).

Does anyone have any thoughts on how to further explore this?  As the situation was more than mildly annoying, and could certainly have been worse, if this is likely to occur for anyone else, I would like to file a PR.

Thanks,
Andrew.