Can't kill hung remote CP copy

[Andrew Gray]

On Fri, 2012-04-13 at 15:59 +0200, suvayu ali wrote:
> On Fri, Apr 13, 2012 at 15:22, Kevin Martin <kevintm at ameritech.net> wrote:
> >
> >
> > On 04/13/2012 05:55 AM, suvayu ali wrote:
> >> On Fri, Apr 13, 2012 at 11:47, Reindl Harald <h.reindl at thelounge.net> wrote:
> >>>> How can I kill the broken cp operation ?
> >>> killall -s SIGKILL cp
> >> This might not work always. I have faced similar issues with processes
> >> waiting to access a filesystem over the network. In these cases if there
> >> is a problem with the network it might get into an UNINTERRUPTIBLE SLEEP
> >> since it is waiting for I/O. The only way to get rid of these processes
> >> is to wait or reboot. In my case this was a tape drive over a network
> >> filesystem.
> >>
> >> The OP can check if this is indeed the case by doing
> >>
> >>   $ ps uf
> >>
> >> If the "cp" process is in UNINTERRUPTIBLE SLEEP, the STATE of the
> >> process should be D. If not then you can ignore my comment.
> >>
> > What happens if you ifdown the nic (if you are on the console
> > obviously)?  Would that allow the cif mount and/or the cp to become
> > available for umount/kill?
> 
> That is a good question. I don't know what would happen then. I guess if
> the filesystem implementation is smart enough to return an error when
> the network goes down, then the I/O wait is over and the application
> gets file read error of some kind and "wakes up" from its
> UNINTERRUPTIBLE SLEEP. But then, this is just a hypothesis which I
> cannot test (I do not have admin privileges to test this).
> 
> -- 
> Suvayu
> 
> Open source is the future. It sets us free.

Thanks for your help

I will try all the suggestions next time, including disabling the NIC 
to see if it free's the CP or allows umount ?



-- 
Andrew Gray <andrewg at linnetsol.co.uk>
Linnet Solutions Ltd