Trouble killing processes in SysV/AT

[Stan Friesen]

In article <3951 at killer.UUCP> wnp at killer.UUCP (Wolf Paul) writes:
>Can anyone enlighten me as to what causes a process to become "immortal"
>in System VR2?
>
>I have encountered this a number of times, where it would be impossible
>even for root to kill a process;
>
>The only way to get rid of such an immortal process seems to be to reboot,
>which is rather drastic.
>
>What causes a process to refuse to die? I thought signal 9 (kill) could
>not be intercepted or ignored?
>
	A process that is suspended in the kernal waiting for the completion
of a block I/O request will not continue, even for a signal, until the I/O
has terminated. If a block device fails without generating a failure status
this can result in an immortal process. This is most common with tape drives.
Is there any particular device that is being accessed by all your immortal
processes? If so it may be having hardware problems. 
	There is no way that I know of getting rid of these things short
of rebooting the system. Most of the time these processes are harmless
and can be left alone until you would be rebooting anyway. So, unless
they are causing problems, like locking up your tape drive, don't bother
rebooting. Just try to find the base cause and remove it.
-- 
Sarima Cardolandion			sarima at gryphon.CTS.COM
aka Stanley Friesen			rutgers!marque!gryphon!sarima
					Sherman Oaks, CA