No dice though trying to do the root FS (and thus all child FS at once as well). Trying to back it up to a child FS on the remote system doesn't work, and neither does attempting -F, which seems to ...

During the booting of Solaris, both the / and /usr file systems are mounted read-only and then later, before the boot process is fully complete, remounted read-write. This is all part of the normal ...