[arch-general] Problem with NFS on shutdown

[Paul Marwick]

Martín Cigorraga wrote:
> On Sat, Jan 19, 2013 at 5:55 AM, Paul Marwick <paul.marwick at gmail.com>wrote:
>
>> I've got two machines in my local network that provide NFS shares. One is
>> an old Raidsonic NAS (running a current version of OpenWRT), the other a
>> dedicated server running Slackware). I normally mount the shares manually
>> (the machine that is giving me a problem is a laptop, so its often not
>> connected to my own network).
>>
>> The problem comes when I try to shut the laptop down (or restart it).
>> Unless I've manually unmounted the NFS shares, the machine will hang and
>> fail to shut down. In some instances, I've been able to use CTRL-C to break
>> out of the stall, but frequently, I can only turn the machine off, which is
>> not exactly ideal.
>>
>> I've been playing with the nfs exports, currently have the following:
>>
>> /mnt/sda2/stor 192.168.1.0/255.255.255.0(rw,**
>> sync,no_wdelay,nohide,no_root_**squash)<http://192.168.1.0/255.255.255.0(rw,sync,no_wdelay,nohide,no_root_squash)>(this is on the Raidsonic)
>>
>> and
>>
>> /mnt/sda2/stor 192.168.1.0/255.255.255.0(rw,**
>> sync,no_wdelay,nohide,no_root_**squash)<http://192.168.1.0/255.255.255.0(rw,sync,no_wdelay,nohide,no_root_squash)>on the Slackware server.
>>
>> The problem is specific to Arch - I've got two other distros installed on
>> the laptop (though Arch is my usual OS). From SalineOS or Salix, the laptop
>> will shut down or restart without having to manually unmount the NFS shares
>> prior to shutdown.
>>
>> I suspect I've not got something set up correctly in systemd, but I'm
>> currently at a loss to work out what. If I manually unmount the shares
>> before shutdown, there is no problem. I've also tried adding the unmount to
>> /etc/rc.local.shutdown, but that doesn't work - the system still hangs
>> during shutdown. I'm sure that rc.local.shutdown is being executed - if I
>> shut down without the shares mounted, I can see messages that they are not
>> mounted.
>>
>> I'm not sure if I should be looking at the NFS export parameters on the
>> hosts, or systemd on the laptop, though I've tried some variations on the
>> exports without changing the behaviour.
>>
>> Does anyone know what I should be looking at to solve this?
>>
>> Paul.
>>
>>
> Same issue here with NFS4 (both laptop and NAS are Arch), if I find what's
> happenings I post back.
I've had a suggestion that the problem may be due to NetworkManger - if 
the network goes down before the NFS shares are unmounted, the sort of 
hang that I'm seeing will happen.

I am using NetworkManager, so it does seem to be a possibility. I'm not 
sure how to check at what point in the shutdown cycle the network is 
disabled. I have a couple of ways of testing it (one possibility may be 
to try a wired network, which should connect and disconnect 
independently of NetworkManager), so I'll post back if I can prove or 
disprove the theory.

The other option is to replace NetworkManager with wicd (which, so far 
as I can remember does not disconnect the network when the desktop is 
shut down).

I will do some testing and post back the results. It would be 
interesting if anyone knows how the shut down sequence works, especially 
when the network is disconnected.

Paul.