br...@nmsu.edu (Brook Milligan) writes:
>> On May 13, 2019, at 3:43 AM, Michael van Elst <mlel...@serpens.de> wrote:
>>
>> br...@nmsu.edu (Brook Milligan) writes:
>>
>>> # ps -lp 4904
>>> UID PID PPID CPU PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND
>>> 0 4904 1 1968 127 0 9924 1160 tstile D ? 0:00.00 disklabel sd0
>>
>>> What exactly does the 'tstile' mean?
>>
>> It means, that the process is waiting for a mutex. There is no information on
>> what mutex it is waiting on, probably something related to a disk driver.
>>
>> You can use the 'crash' utility or the DDB kernel debugger to get a
>> backtrace. This shows where the process is waiting, which is a good
>> hint on what it is waiting for.
>What is your suggestion for how to use 'crash'? I have never done that so I
>am not sure what commands are available once I run it. Running ps in crash
>does not seem to reveal much, but I'm not really sure how to interpret all the
>hex information.
There is a backtrace command, like (the 0t means 'decimal number'):
bt/t 0t$PID
or
bt/a $LWPADDRESS
the LWPADDRESS can be found in the ps output ("STRUCT LWP *").
You only need the latter to select between different threads of a process
or to select a kernel thread. That's not necessary for disklabel.
>This sounds like the only option is to get someone to power cycle it. Is that
>correct? It would still be nice to know what happened so I can understand
>what to do in the future; hence my questions about troubleshooting.
You might try to reboot, but this may then hang completely and then you still
need a hard reset. A 'reboot -n' that doesn't try to sync disks probably works.
--
--
Michael van Elst
Internet: mlel...@serpens.de
"A potential Snark may lurk in every tree."
