Is it possible to do a remote update of a suse box from 9.1 to the
current version of openSUSE safely? (that is, without running the risk
that a reboot will leave the box inaccessible through the network).

I have a 9.1 box in a data center a few miles away. It's a headache to
get physical access to the box. I'd like to upgrade the OS because there
are a number of apps that need to be updated, and it's getting tougher
to do it through YAST on an old version.

Does anyone have a pointer to an upgrade how-to?

Is it even possible to do without physical access?