[TriLUG] Sun Jumpstart experts?

[Michael Alan Dorman]

"Ben Pitzer" <uncleben at mindspring.com> writes:

> Actually, they do have to be on the same subnet.

That is not a real requirement at all.  period.

Really, a jumpstart is nothing but a net-boot, plus an nfs-root.

Sun provides a couple of tools to perform a couple of tasks that are
peculiar to setup (partitioning and the like), and seems to go to
great lengths to establish this mystique around jumpstart, but there
is really *no* magic involved.  I wrote *all* my own scripts for
things, and didn't use any of the standard sun scaffolding.

Heck, there's a guy who's implemented a tool called FAI for Debian
that bears a painful resemblance to jumpstart.  I felt all too at home
when I started using it.

In fact, for reasons that escape me, he's looking to extend it to
doing Solaris installs as well!  I suspect it's just perversity.

So, anyway, the only requirement is that you be able to net-boot and
mount an nfs-root.  Because of the requirements of net-booting---that
every net-booting method in the universe (at least that I am aware of)
relies on broadcasts, which *are* segment-specific---it is often
believed that Jumpstart requires boxes to be on their own segments,
but that really isn't the case; you just have to work around your
net-boothing requirements.  DHCP is an effective solution, and, in my
experiments, a little faster.

> We use them here at RR, and must build all boxes on one subnet, then
> reconfigure the network info to put it on another.  I prefer it that
> way, because we can segregate that subnet from the world so that if
> for some odd reason we have to leave a box unpatched to go work on
> another issue or emergency, it isn't out where the world could
> potentially see it and crack it.

Now these are some good reasons for having a special jumpstart
segment---though I always just patched boxes as start of my
jumpstarts.  Also related is the issue of jumpstart requiring NFS,
which is to network security what leaving your fly down is to being
suave and debonaire...

Mike.