[olug] Killing a process

[Chris St. Pierre]

On Mon, 2 Jul 2007, Travis Owens wrote:

> Here's a stumper... had a box running a process which writes to a
> piped process. The piped process died unexpectedly. The initial
> process was then stuck in a "waiting" or as top displayed "swapped
> out" mode. It was using 99% of the CPU as well, but we could not kill
> it.
>
> Has anyone experienced this before, and is there a way to recover w/o rebooting?

'ps aux' will tell you the state of the process.  If it's in state
"D", that's an uninterruptable sleep, usually waiting for I/O -- quite
possible in this case.  You _cannot_ kill process in state D; you must
restart the box.

Frequently, though, process in state D won't actually consume any
processor, they'll just qualify as an enqueued process for uptime(1)
numbers.  Those can be safely ignored until normal scheduled
downtime.  It sounds like you weren't so lucky as that.

Chris St. Pierre
Unix Systems Administrator
Nebraska Wesleyan University
----------------------------
LOPSA Sysadmin Days: Professional Training for Professional SysAdmins
August 6-7, Cherry Hill, NJ
http://lopsa.org/SysadminDays