ONTAP Discussions

NFS hung mounts


Hi Folks,

Apologies if this isn't the right venue since this is probably more about OS admin than NetApp specifically, but we are using NetApp ONTAP for NFS NAS so I figured I'd try because the quality of response here has been great.


We've just had a minor planned network "blip" (5s-15s) that couldn't be avoided due to where the change was happening on the network core.  I didn't think it would be a big deal but we still ended up having a ton of hung NFSv3 hard mounts that couldn't be resolved without rebooting the affected Linux systems.


The systems ranged from Debian 8 / CentoOS6 to Ubuntu 20.04.  Mounts have been defined in fstab with varying options, from simply 'defaults', to '_netdev,nofail'.  Some hosts weren't affected at all. 


It's 2021 and to me it seems wild that a modern Linux OS can't gracefully recover from a 5-15s outage.  Am I missing some tricks for getting more graceful recovery on these systems?  Was there something I could do from the client end to get the mount to drop completely and remount?


Longer term I'm hoping to move clients over to a new SVM that enforces NFSv4.1+, but that's still a way off and I'll have to contend with NFSv3 for some time in this infra.  Then again I'm not sure that changing the protocol version will help much - I'm not an NFS guru.


Thanks everyone!





you can try retrans mount point option.


There are also other option you can test:



good luck!

Jonathan Colón | Blog | Linkedin