Re: [gentoo-user] NFS mount not properly unmounting during shutdown/reboot

[Alan McKinnon <alan.mckinnon@gmail.com>]

On 10/06/2013 16:36, Tanstaafl wrote:
> On 2013-06-10 6:38 AM, Alan McKinnon <alan.mckinnon@gmail.com> wrote:
>> On 10/06/2013 12:34, Tanstaafl wrote:
>>> If I remember to manually unmount the NFS mount before initiating the
>>> reboot/shutdown, it doesn't hang.
>>>
>>> I'm guessing that it hangs at /var because it is the last mountpoint
>>> defined in my /etc/fstab?
>>>
>>> So... any pointers on where to look for a resolution would be
>>> appreciated.
>>>
>>> Resolution being, if I can manually unmount it fine, why can't the
>>> system auto-unmount it?
> 
>> Let's get some facts to work with
>>
>> can you post your fstab,
> 
> Fyi, I don't have either of these auto-mounting in fstab, but here it is:
> 
> # <fs>             <mountpoint>    <type>           <opts>   <dump/pass>
> 
> # NOTE: If your BOOT partition is ReiserFS, add the notail option to
> # opts.
> /dev/sda1           /boot           ext2            noauto,noatime  1 2
> /dev/sda2           none            swap            sw              0 0
> /dev/sda3           /               ext3            noatime         0 1
> /dev/sda4           /backups        ext3            noatime         0 2
> /dev/vg2/home       /home           reiserfs        noatime         0 0
> /dev/vg2/usr        /usr            reiserfs        noatime         0 0
> /dev/vg2/var        /var            reiserfs        noatime         0 0
> /dev/cdroms/cdrom0  /mnt/cdrom      iso9660         noauto,ro       0 0
> /dev/fd0            /mnt/floppy     auto            noauto          0 0
> 
> # NOTE: The next line is critical for boot!
> none                /proc           proc            defaults        0 0
> 
> # glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for
> # POSIX shared memory (shm_open, shm_unlink).
> # (tmpfs is a dynamically expandable/shrinkable ramdisk, and will
> #  use almost no memory if not populated with files)
> shm                 /dev/shm        tmpfs      nodev,nosuid,noexec  0 0
> 
>> rc-update show,
> 
>  # rc-update show
>               apache2 |      default
>              bootmisc | boot
>           consolefont | boot
>                 devfs |                                        sysinit
>         device-mapper | boot
>                 dmesg |                                        sysinit
>               dovecot |      default
>                  fsck | boot
>              hostname | boot
>               hwclock | boot
>              iptables |      default
>               keymaps | boot
>             killprocs |                        shutdown
>                 local |      default nonetwork
>            localmount | boot
>                   lvm | boot
>               mailman |      default
>               modules | boot
>              mount-ro |                        shutdown
>                  mtab | boot
>                 mysql |      default
>              net.eth0 |      default
>                net.lo | boot
>              netmount |      default
>            ntp-client |      default
>                  ntpd |      default
>               postfix |      default
>                procfs | boot
>                  root | boot
>               rpcbind |      default
>             savecache |                        shutdown
>                  sshd |      default
>                  swap | boot
>             swapfiles | boot
>                sysctl | boot
>                 sysfs |                                        sysinit
>             syslog-ng |      default
>          termencoding | boot
>        tmpfiles.setup | boot
>                  udev |                                        sysinit
>            udev-mount |                                        sysinit
>        udev-postmount |      default
>               urandom | boot
>            vixie-cron |      default
>                xinetd |      default
> 
> 
>> /etc/exports on the NFS server
> 
> Well... there is no 'NFS Server', these are two QNAP boxes that I can
> enable NFS on... I guess there may be a way to command-line into them to
> check that, so if it critical to answering the question, I'll see what I
> can do. All I know for sure is, if I manually unmount it with umount
> /mnt/qnap-mountpoint, it unmounts immediately.
> 
>> and the mount options used for the NFS mounts?
> 
> The command I use to mount it is:
> 
> mount -t nfs -o mountproto=tcp qnap1:/backups /mnt/qnap1
> 
> Thanks Alan, hopefully something jumps out at you...
> 

I'm not familiar with QNAP but there's nothing for it in fstab, so I
presume running the relevant app on your end magically mounts the remote
share without consulting fstab?

It all looks very much like your init system is simply not umounting the
shares at all so when it tries to remount / ro near the end, this fails.

The simplest way around this is to add nfsmount to the default runlevel.
This will work today as it reads /etc/fstab at startup to mount stuff
and your fstab has no nfs shares in it.
It reads /etc/mtab at shutdown to umount stuff and your QNAP share will
be in that file.

I simulated it here and that's the result I got. But this is gentoo, and
everything might change tomorrow so YMMV :-)

You could also write a scriptlet to do the umount and put it in
/etc/conf.d/local - see /etc/init.d/local for details



-- 
Alan McKinnon
alan.mckinnon@gmail.com