Contingency planning for System Failure

I have inhereted a Solaris 8 server which is running an important application in our production environment.
The dilema is that the server has just one internal hard drive I believe it was installed using jump start, it does not even have a CD ROM drive and root is not mirrored (since there is only one hard drive)
I cannot take the server down for any reason.
The best I could do is take the backup of the entire server from root on a tape using netbackup.
The only comforting aspect is that I have a server similar to this server which I can use in case of emergency which does have a CD ROM drive.
My question is, if the server dies, what can I do now to restore with minimum down time on to the spare server

I was inclined and please correct me if I am wrong is to create a flash archive from root of this server on to another server's spare drive.

If the server dies I can use the spare server, boot it from solaris 8 CD and do an installation using flash archive i have created.

Please excuse my ignorance, but I surely appreciate some guidence.

Thanks

Since you have a spare server to use just in case . . . do a trial run. Recover to that server and bring it up to see if what you did works. You could recover to it, disconnect it from the network, and boot it up. That way you could test without interfering with the running server. I did this with a similar situation I have, and it helped me uncover some complications that I would have to deal with. Your combination is probably somewhat different than mine, so your complications may differ.

minimum downtime is still not achieved. your method of creating a flar image to be used on a new disk might work, but why dont you first think of getting a 2nd hdd to mirror the root disk. In case of any failures, recovery is easier and unlikely downtime is required at all.