Date: Fri, 1 Aug 2014 06:42:17 +1000
From: NeilBrown <neilb@suse.de>
To: Ben Greear <greearb@candelatech.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: Killing process in D state on mount to dead NFS server.
Message-ID: <20140801064217.01852788@notabene.brown>
In-Reply-To: <53DA8443.407@candelatech.com>
References: <53DA8443.407@candelatech.com>
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On Thu, 31 Jul 2014 11:00:35 -0700 Ben Greear <greearb@candelatech.com> wro=
te:

> So, this has been asked all over the interweb for years and years, but
> the best answer I can find is to reboot the system or create a fake NFS
> server somewhere with the same IP as the gone-away NFS server.
>=20
> The problem is:
>=20
> I have some mounts to an NFS server that no longer exists (crashed/powere=
d down).
>=20
> I have some processes stuck trying to write to files open on these mounts.
>=20
> I want to kill the process and unmount.
>=20
> umount -l will make the mount go a way, sort of.  But process is still hu=
ng.
> umount -f complains:
>   umount2:  Device or resource busy
>   umount.nfs: /mnt/foo: device is busy
>=20
> kill -9 does not work on process.

Kill -1 should work (since about 2.6.25 or so).
If it doesn't please report the kernel version and=20
 cat /proc/$PID/stack

for some processes that cannot be killed.

NeilBrown

>=20
>=20
> Aside from bringing a fake NFS server back up on the same IP, is there any
> other way to get these mounts unmounted and the processes killed without
> rebooting?
>=20
> Thanks,
> Ben
>=20


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