If you are running a JupyterHub on Kubernetes and use NFS for home directory storage (a common occurance), I highly recommend the following settings: singleuser: extraEnv: # notebook server writes secure files that don't need to survive a # restart here. Writing 'secure' files on some file systems (like # Azure Files with SMB or NFS) seems buggy, so we just put runtime dir on # /tmp. This is ok in our case, since no two users are on the same # container.