CentOS - Feb 2016 - nfs stuck, don't know what processes to kill

My NFS server is up and other clients can access x. One particular client
can't. I tried to unmount the NFS share:

[root at nfsclient ~]#  umount -f /disk/x
umount2: Device or resource busy
umount.nfs: /disk/x: device is busy
umount2: Device or resource busy
umount.nfs: /disk/x: device is busy

If I use df or lsof to try to figure out what process to kill, they hang. I
am reluctant to just reboot, as many other users are getting stuff done.
dmesg doesn't show anything useful.

How to get unstuck?

thanks,
Dave

Try "umount -fl"            ('eff el')

On Tue, Feb 2, 2016 at 1:58 PM, Dave Burns <tburns at hawaii.edu> wrote:
> My NFS server is up and other clients can access x. One particular client
> can't. I tried to unmount the NFS share:
>
> [root at nfsclient ~]#  umount -f /disk/x
> umount2: Device or resource busy
> umount.nfs: /disk/x: device is busy
> umount2: Device or resource busy
> umount.nfs: /disk/x: device is busy
>
> If I use df or lsof to try to figure out what process to kill, they hang. I
> am reluctant to just reboot, as many other users are getting stuff done.
> dmesg doesn't show anything useful.
>
> How to get unstuck?
>
> thanks,
> Dave
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
>


-- 
Matt Phelps
System Administrator, Computation Facility
Harvard - Smithsonian Center for Astrophysics
mphelps at cfa.harvard.edu, http://www.cfa.harvard.edu

Dave Burns wrote:
> My NFS server is up and other clients can access x. One particular client
> can't. I tried to unmount the NFS share:
>
> [root at nfsclient ~]#  umount -f /disk/x
> umount2: Device or resource busy
> umount.nfs: /disk/x: device is busy
> umount2: Device or resource busy
> umount.nfs: /disk/x: device is busy
>
> If I use df or lsof to try to figure out what process to kill, they hang.
> I
> am reluctant to just reboot, as many other users are getting stuff done.
> dmesg doesn't show anything useful.
>
> How to get unstuck?
*IF* I understand what you're saying, on that one client, you're trying
to
umount the nfs share. Is that the case?

IF that is the case... is autofs running? If so, service autofs stop, and
you should be able to umount it.

       mark

umount -fl /mount/point 
And configure it after with autofs 

Sent from my iPhone
> On Feb 2, 2016, at 20:00, Phelps, Matthew <mphelps at
cfa.harvard.edu> wrote:
> 
> Try "umount -fl"            ('eff el')
> 
>> On Tue, Feb 2, 2016 at 1:58 PM, Dave Burns <tburns at hawaii.edu>
wrote:
>> 
>> My NFS server is up and other clients can access x. One particular
client
>> can't. I tried to unmount the NFS share:
>> 
>> [root at nfsclient ~]#  umount -f /disk/x
>> umount2: Device or resource busy
>> umount.nfs: /disk/x: device is busy
>> umount2: Device or resource busy
>> umount.nfs: /disk/x: device is busy
>> 
>> If I use df or lsof to try to figure out what process to kill, they
hang. I
>> am reluctant to just reboot, as many other users are getting stuff
done.
>> dmesg doesn't show anything useful.
>> 
>> How to get unstuck?
>> 
>> thanks,
>> Dave
>> _______________________________________________
>> CentOS mailing list
>> CentOS at centos.org
>> https://lists.centos.org/mailman/listinfo/centos
> 
> 
> 
> -- 
> Matt Phelps
> System Administrator, Computation Facility
> Harvard - Smithsonian Center for Astrophysics
> mphelps at cfa.harvard.edu, http://www.cfa.harvard.edu
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos

Thanks. How did I miss that -l switch? Unfortunately, I went into panic
mode and just rebooted, but I'll know next time.
Dave

On Tue, Feb 2, 2016 at 9:00 AM, Phelps, Matthew <mphelps at
cfa.harvard.edu>
wrote:
> Try "umount -fl"            ('eff el')
>
> On Tue, Feb 2, 2016 at 1:58 PM, Dave Burns <tburns at hawaii.edu>
wrote:
>
> > My NFS server is up and other clients can access x. One particular
client
> > can't. I tried to unmount the NFS share:
> >
> > [root at nfsclient ~]#  umount -f /disk/x
> > umount2: Device or resource busy
> > umount.nfs: /disk/x: device is busy
> > umount2: Device or resource busy
> > umount.nfs: /disk/x: device is busy
> >
> > If I use df or lsof to try to figure out what process to kill, they
> hang. I
> > am reluctant to just reboot, as many other users are getting stuff
done.
> > dmesg doesn't show anything useful.
> >
> > How to get unstuck?
> >
> > thanks,
> > Dave
> > _______________________________________________
> > CentOS mailing list
> > CentOS at centos.org
> > https://lists.centos.org/mailman/listinfo/centos
> >
>
>
>
> --
> Matt Phelps
> System Administrator, Computation Facility
> Harvard - Smithsonian Center for Astrophysics
> mphelps at cfa.harvard.edu, http://www.cfa.harvard.edu
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
>


-- 
This email is:    [ ] request action  [ ] request info   [x] fyi        [ ]
social
Response needed:  [ ] yes          [x] up to you  [ ] no
Time-sensitive:   [ ] immediate    [ ] soon       [x] none
http://www.43folders.com/2005/09/19/writing-sensible-email-messages

On Tue, Feb 2, 2016 at 9:23 AM, <m.roth at 5-cent.us> wrote:
> Dave Burns wrote:
> > My NFS server is up and other clients can access x. One particular
client
> > can't. I tried to unmount the NFS share:
> >
> > [root at nfsclient ~]#  umount -f /disk/x
> > umount2: Device or resource busy
> > umount.nfs: /disk/x: device is busy
> > umount2: Device or resource busy
> > umount.nfs: /disk/x: device is busy
> >
> > If I use df or lsof to try to figure out what process to kill, they
hang.
> > I
> > am reluctant to just reboot, as many other users are getting stuff
done.
> > dmesg doesn't show anything useful.
> >
> > How to get unstuck?
>
> *IF* I understand what you're saying, on that one client, you're
trying to
> umount the nfs share. Is that the case?
>
> IF that is the case... is autofs running? If so, service autofs stop, and
> you should be able to umount it.
>
>        mark
>
> # service autofs stop results in fail. Maybe need #rm /var/run/autofs.pid?
Dave