I just recently had to migrate a large NFS share due to storage issues. A new NFS share was prepared on a different system, files were coppied over, all the nasty UID/GID related permissions taken care of and what was left was to remount the share on the servers that used it.

Since it wasn’t that critical a simple umout /mnt/data && mount /mnt/data was enough. Quick check that the remote filesystem was visible, everything seemed OK, on to other things… Until..

A while after one of the engineers comes with “the web server does not server my files!”. Yes an nginx is running on these servers and is serving files from this share. A dockerized nginx.

Wait, how come, all the files are there, lets look inside the container:

$ ls /mnt/data
ls: cannot access '/mnt/data': Stale file handle

Oh, somehow docker volume mount and the nfs mount werent updated.

A simple container restart was enought to get things running again.