Consistent file system hang with RELENG_6 of today ...

[Marc G. Fournier]

Oh, before I forget ... how do you break to DDB from a serial console? 
I'll be running a Portmaster for this ...

On Fri, 29 Jul 2005, Robert Watson wrote:

>
> On Thu, 28 Jul 2005, Marc G. Fournier wrote:
>
>> 'k, I'm starting to play with 6.x, for our new server ... my priority right 
>> now is to just have it run the existing 'jail' environments from my 4.x 
>> machine, while I work on getting all of our servers up to 6.x, and then 
>> will worry about the jail's themselves ...
>> 
>> When I try and startup the 4.x jail on my 6.x machine, it "hangs" the file 
>> system that the jail directory hierarchy happens to be mounted on though 
>> ... twice in a row so far ...
>> 
>> Now, I'm suspecting (and am going to try without it) that it might be 
>> because I'm mounting devfs within the 4.x jail, but even then, it shouldn't 
>> hang things up, only generate a whack of errors ...
>> 
>> I have a good dump (CTL-ALT-ESC -> panic), but do not have a clue what to 
>> offer from within there that might be of any use ...
>> 
>> If anyone is interested ... ?
>
> If you can get into DDB and have serial console output, the following would 
> be useful:
>
> The output of 'show pcpu'
>
> The output of 'show pcpu X' for each present cpu, starting with 0.
>
> The output of 'ps'
>
> The output of 'trace' for the currently running thread, and each non-idle 
> thread shown in the show pcpu output
>
> The output of 'show lockedvnods'
>
> It would also be useful if, relating to the startup of the jail, you can 
> identify the point in the jail boot where it wedges, and if you hit Ctrl-T, 
> what process is shown as running and what state it is in, and using DDB, 
> trace that process.
>
> If you could show the trace output for each process listed in "show 
> lockevnods".
>
> Likely, there is a leaked lock or a low buffer condition.  However, once we 
> have the above output we should be able to say more.  The above will 
> hopefully tell us whether it's a vnode deadlock, and ideally, the approximate 
> source.
>
> Robert N M Watson
>
>

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 7615664