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Re: Ctrl-Alt-Del problem

Bruce Perens:
> I think if your system hangs in shutdown it is hanging in "unmount". Often
> this is an unmount of a partition on a non-responding NFS host. Unmount
> should time out, I guess.

I too noticed this problem with 0.93R6 (sysvinit-2.57b-1) - if I hold
down ctrl-alt-del for too long (or press it quickly several times), it
will hang after the "sending TERM signal" message.  This has nothing
to do with NFS - this happens on my non-networked home box.  If I press
ctrl-alt-del only once and for very short time, it never hangs.  Sounds
like a bug in init - maybe some problem with the SIGINT handler if it
gets called twice in a row, or something like this.

umount in util-linux (2.4 and 2.5) has a misfeature: the NFS umount RPC
call does time out, but if it fails, the filesystem is not unmounted.
This means it is not possible to umount a NFS filesystem if the server
is not responding.  Older versions of umount don't have this problem,
because they don't send any RPC calls.  The right thing to do, I think,
is to send the RPC call (maybe with an option to turn it off) and ignore
any errors (unmount it anyway).  I sent a bug report (with patch) to the
current util-linux maintainer long time ago, but received no reply.


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