Boot hangs in single-user mode

[Andrew Hamilton-Wright]

[ Condensation of earlier comments below ]

On 2013-06-06, at 11:18 AM, Polytropon wrote:

> On Thu, 6 Jun 2013 10:24:52 -0300, Andrew Hamilton-Wright wrote:
>> 
>> 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
> 
> Have you tried hitting the RETURN key several times?
	...
> It's important to identify if the system is _really_ hanging,
> or if the message "just isn't visible"...

I did try that -- I have seen that behaviour before too.  I tried hitting return
a half-dozen times, and have additionally tried waiting (up to 20 min) to
see if it would come back, to no avail.


>> Interestingly, there seems to be a bit of a sequence issue,
>> as I have also seen the mount message appear before the audio
>> system comes up, so occasionally, the last item printed is:
>> pcm0:  <USB audio> on uaudio0
> 
> This seems to indicate that the system is still responding,
> i. e., the kernel is "up and running". Whenever "new" hardware
> is detected, the kernel will issue a console message.

That is a good point -- I will try plugging in an external USB device
at this point, and see what happens then.  It certainly appears that
the system is generally running to me, as well.  I should also mention
that the system does respond nicely to [CTRL]-[ALT]-[DEL], which
triggers the expected reboot process.


>> I am rebooting the machine at the moment as I wish to ensure
>> that I know which physical disk is ada2, so want to boot the
>> machine without it plugged in.
> 
> A suggestion: I tend to keep a tendency to use labels instead
> of device names to identify disks. This is handy in case you're

This is an excellent idea.  I do follow some variant of this (however
work at a high enough level of paranoia that I want to be able to
perform the "did the right drive disappear when I unplugged it"
check just to ensure that I wasn't asleep when making up the labels.
;-)


Thanks for the suggestions -- I will keep looking at it, and will try
adding a USB device once this restore eventually completes.

Thanks,
Andrew.