Thanks Walter, that did help a lot! Looking into it a bit more, this is what it looks like I need to learn about and implement. How does this sound for an extremely broad overview:
Step 1) Cluster the 4 physical servers together (figure out what type of cluster I need, and use Oracle Cluster 4.x on top of Solaris 11.1 or maybe 11.2 beta?)
Step 2) Create Zoneclusters, probably one for each type of OS I need to run (a Sol 8 ZC, and a Sol 10 ZC, and then possibly a Sol 11 ZC to try to migrate the systems up if possible...)
Step 3) Create Logical Domains (LDOMs) for each of my old systems, and put them on the zone clusters, using Oracle VM Server.
In this setup, if a node fails, the virtual system will go down, but I should be able to configure it to start up another node automatically with minimal downtime for the virtual systems?
I realize "I should be" is reaching, since I have virtually zilch cluster experience and limited Solaris experience, but let's rephrase that to "it's possible to". I realize I have a lot of work ahead of me, but thankfully I have no strict time limits to get this implemented and can work one step at a time.
Thanks so much for your help - does this all sound correct so far?
Not sure whether you have found resolution for your requirement.
Recently I have implemented Solaris 11.1 with cluster 4.x to manage hardware failures, though mine is a two node cluster. Used T5-2.
I implemented LDOMs and configured zones inside the LDOMs, all solaris 11.1.
You can also, have the LDOMs running Solaris 10. Snapshot (flar) your currently running solaris versions and restore them into the LDOMs. This requires some additional patches for Solaris 10 to support configuring Solaris 8 zone.
Reading your question , it seems to me that you are confused about the relationship between a physical machine , a LDOM/VM and a Solaris ZONE.
You can have a Solaris ZONE in a Physical Solaris server.
You can have a LDOM/VM in a Physical Solaris server.
You can have a Solaris Zone in a LDOM/VM in a Physical Solaris Server.
YOU CAN NOT HAVE a LDOM/VM in a Solaris ZONE.
If your comment is on my update, thank you for correcting. Last part of it should have been formatted properly.
NO the OP says in post 2 above that he will put LDOM's in the ZONE clusters ........
If he did that these LDOMS would not be part of the solaris clusterd zones but would exist outside the solaris zone cluster config.
its ofcource possible to clusters LDOMs on different servers as well.
ANyway I understand why the OP is sligthly disoriented whith all the options.