Consistent file system hang with RELENG_6 of today ...

[Marc G. Fournier]

'k, this is turning out to be alot of fun ... the only machines I have 
here that I can use to talk to the portmaster are Windows boxes ... can 
you recommend a client for windows that would do good logging similar to 
what 'script' does under FreeBSD?  :(

On Fri, 29 Jul 2005, Robert Watson wrote:

>
> On Fri, 29 Jul 2005, Marc G. Fournier wrote:
>
>> Oh, before I forget ... how do you break to DDB from a serial console? I'll 
>> be running a Portmaster for this ...
>
> Compile BREAK_TO_DEBUGGER into the kernel.  Then issue a serial break and it 
> should go into the debugger if the low-level console is set to the serial 
> port.
>
> On my port-master, I issue a telnet break using "send break" after hitting ^] 
> to generate a serial break for a serial port hooked up to TCP.
>
> There's also ALT_BREAK_TO_DEBUGGER, which is documented in NOTES, and 
> provides for an alternative key sequence that doesn't use a break signal.
>
> Robert N M Watson
>
>> 
>> 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
>> 
>
>

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