multi-version jumpstart

[Jamie Novak]

I currently have a jumpstart server setup in such a way that we can
specify on a "configure" command-line various install options (which
4.x-RELEASE we want to use, server config type, etc.). This part is
working great and has saved us a ton of time.

Now that 5.x is moving into the realm of being stable enough for our
production uses, we're looking into making use of some of the
SMP-related goodies in that release line. Unfortunately, I do not seem
to be able to get our jumpstart server to be able to dynamically
install both 4.x and 5.x targets from the same machine.

I'm able to get the jumpstart server to export the 5.3-RELEASE partition
and pass the GENERIC kernel and install.cfg over to the network-booting
machine, but when it comes time to actually NFS mount the install
partition on the target server to run the install, it returns an NFS
error:

	mount_nfs -P 10.x.x.x:/releases/5.3-RELEASE/ /dist
	mount_nfs: Can't update /var/db/mounttab for 10.x.x.x:/releases/5.3-RELEASE
	mount_nfs: /dist: operation not supported by device

I'm assuming the problem is related to the fact that the jumpstart
server is running 4.x-RELEASE, while the OS I'm trying to install on the
target server (and the kernel that's attempting to NFS mount the
partition) is from the 5.x line and they're fighting over mounttab
magic.

Does anybody know if this kind of thing is possible? If so, what did you
do to enable such a configuration to work? (Would it be possible to
install both 4.x and 5.x on network-booting clients if the jumpstart
server was 5.x instead of 4.x as it is now?)

I'd really like to avoid having to build a second jumpstart server just
to get 5.x installs working, but I'm afraid it's looking like that's the
way I'll need to go... Any tips would be most appreciated.

-Jamie