lx: nodiratime with tmpfs function not implemented

[ismell]

Trying to get the unifi-video service installed in an ubuntu 16.04 lx zone. It sets up a tmpfs directory as part of the init script:

# mount -t tmpfs -o noatime,nodiratime,noexec,size=15%,mode=0700,uid=112 tmpfs /var/cache/unifi-video
mount: mount tmpfs on /var/cache/unifi-video failed: Function not implemented

Removing the nodiratime option allows the mount command to work.

Using: SmartOS (build: 20200826T232925Z)