Process does not respond to any signals??

Process does not respond to any signals??

Post by pa.. » Wed, 17 Jul 1996 04:00:00



Hello:
I have a process setuid to root. It is controlling a SCSI device.
Sometimes the process get hung (still have not figured out why
and what sequence of the events cause this) and does not respond
at all even for kill -9. I am sending the kill signal as a root.
I have put some timeouts in the programs when it is reading data
but the progrm is not responding to any signals. What causes this
and how can i recover from this? I am running under SOlaris2.5
on UltraSparc.
Thanks.


 
 
 

Process does not respond to any signals??

Post by Kurt J Lan » Wed, 17 Jul 1996 04:00:00



>Hello:
>I have a process setuid to root. It is controlling a SCSI device.
>Sometimes the process get hung (still have not figured out why
>and what sequence of the events cause this) and does not respond
>at all even for kill -9. I am sending the kill signal as a root.
>I have put some timeouts in the programs when it is reading data
>but the progrm is not responding to any signals. What causes this
>and how can i recover from this? I am running under SOlaris2.5
>on UltraSparc.
>Thanks.

We have seen the same sort of thing under SCO. We speculate
that a SCSI device done message is not being received by the
host, either because the device didn't send it or the cable
was noisy, etc. etc.... Anyway, since the operation never
"terminates" the kernel never reschedules the process,
therefore it never "sees" a signal. We don't know any way to
fix it other than a reboot. Hope this helps, or at least
gives food for thought.
--
--


 
 
 

Process does not respond to any signals??

Post by Richard A. Farra » Thu, 18 Jul 1996 04:00:00




> >Hello:
> >I have a process setuid to root. It is controlling a SCSI device.
> >Sometimes the process get hung (still have not figured out why
> >and what sequence of the events cause this) and does not respond
> >at all even for kill -9. I am sending the kill signal as a root.
> >I have put some timeouts in the programs when it is reading data
> >but the progrm is not responding to any signals. What causes this
> >and how can i recover from this? I am running under SOlaris2.5
> >on UltraSparc.
> >Thanks.

> We have seen the same sort of thing under SCO. We speculate
> that a SCSI device done message is not being received by the
> host, either because the device didn't send it or the cable
> was noisy, etc. etc.... Anyway, since the operation never
> "terminates" the kernel never reschedules the process,
> therefore it never "sees" a signal. We don't know any way to
> fix it other than a reboot. Hope this helps, or at least
> gives food for thought.
> --
> --


If the status of the running process is D, the process has been
swapped out to disk, and the process will not respond to _any_ signals
until it has been swapped back in.

To determine if this is the case do
ps -elf | grep yourprocess

If the second field is "D", this is what's happening.

--
Richard A. Farrar

 
 
 

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