Comment 5 for bug 1313513

mountall blocks only those parts of the boot process that are marked as depending on the relevant filesystem. And by default, mountall assumes that the 'filesystem' event should not be emitted until all filesystems under /usr and /var are mounted. If this is not the correct policy for your use case, you can override the behavior with the 'nobootwait' option in /etc/fstab.

However, in this case that would seem to just be a workaround for the ceph client itself blocking on the 'filesystem' event when it shouldn't. Are you using the Ubuntu ceph package on the client? If so, this bug should be reassigned there.