The courses would be spread amoungst multiple instances.
I have left the requirements vague as I am open to suggestions. Please advise.
I am thinking:
2x dual CPU dual core (2 machines with 4 cores each) with 4GB of RAM (8GB if we use VMWARE) hooking them up to a SAN (or cross mounting NFS)(for the storage) and master master replication for mySQL
Placing the two machines behind a load balancer and splitting the backup tasks between machines.
Im also interested to know peoples experience with running moodle on VMWARE for medium sized installations (100+ courses)!
Thanks in advance for your help.