Mount order for directories

[Paul Howarth]

Nick Pierpoint wrote:
> Hello all.
> 
> If I have a disk mounted on /opt:
> 
> 	mount /dev/hdb1 /opt
> 
> but then also have another disk mounted on /opt/thensome
> 
> 	mount /dev/hdb2 /opt/thensome
> 
> In /etc/fstab I'd have something like:
> 
> 	LABEL=/opt          /opt           ext3 defaults 1 2
> 	LABEL=/opt/thensome /opt/thensome  ext3 defaults 1 2
> 
> My question is will this always work? When directory mounts have a
> degree of inter-dependence how do you specify the mount order? Does the
> mount process religiously follow through the order in fstab?

"man 8 mount" suggests that mount does choose the correct order to use, 
because if you look at the -F option to fork a separate mount process for each 
filesystem, it says "This will do the mounts on different devices or different 
  NFS servers in parallel. This has the advantage that it is faster; also NFS 
timeouts go in parallel. A disadvantage is that the mounts are done in 
undefined order. Thus, you cannot use this option if you want to mount both 
/usr and /usr/spool." The implication is therefore that if you don't use the 
-F option, mount will get the order right.

Paul.