(3.4.0‐3.9.0) Updating a cluster to include an EFS fs with encryption in transit fails - mindvaultdev/aws-parallelcluster GitHub Wiki
Updating a cluster to include an efs fs with encryption in transit will fail to mount due to the missing tls option. This can potentially result in communication with filesystems without encryption in transit. To work around this issue, remove the shared storage from the config file and mount it as a custom action script.
mount -t efs -o _netdev,noresvport,tls <fs-id>:<share-dir> <dir>
https://docs.aws.amazon.com/parallelcluster/latest/ug/custom-bootstrap-actions-v3.html