mount as ro for users, rw for root?

[Sabuj Pattanayek]

> multiply mounting a NFS export is OK.  Multiply mounting an iSCSI
> volume (a LUN, seen as a disk to Linux) is really bad, unless you're

I'm going to try mounting a test fs under two mount points as rw and
see what happens. With the rw and ro mounted in two different
locations, perhaps one could use the "noatime" mount option for the ro
mount point if the atimes don't matter to you.

The only other alternative which worked (tested) is to mount it rw
under a root only accessible area:

mkdir -p /rootOnly/foo
chown root:root rootOnly
chmod 700 /rootOnly
mount -t fsType /dev/somedev /rootOnly/foo

setup an nfs export to localhost of the fs, this can be exported (rw)
rather than explicitly (ro) since the following seemed to work and
disallow  write access:

mount -t nfs -o ro localhost:/rootOnly/foo /everyone/foo

Just make sure they can't run nfs in user land or something that might
allow them to mount nfs in their home dir, otherwise to be safe you
could also export it (ro) as well.

HTH,
Sabuj Pattanayek