Is it possible to add storage space to our start edition ESX by adding an external hard drive? I know that SAN is not supported. So how do I go about adding additional space to our maxed out server? Possibly so I can store VM's not in use on the storage space and move them to the local storage when I need to use them? Any ideas, I'm going around in circles with support and sales. Seems no one can give me a straight answer they just keep linking me to documents I have already read or referenced questions about.
Also can someone explain to me what VMFS does and what problems it can cause me by only being available on local storage for the starter edition?
You can used NAS/NFS for this. It will not be VMFS but you can use it to store and run VM's. What type of server do you have, optionally you could add some additional external SCSI disk to it.
Chapter 5 of the server config guide details how to setup NAS/NFS.
http://www.vmware.com/pdf/vi3_301_201_server_config.pdf
New Storage Technologies: iSCSI, NAS and VMFS 3.0 - http://www.vmware-tsx.com/download.php?asset_id=20
Choosing and Architecting Storage for your Environment - http://download3.vmware.com/vmworld/2006/adc0135.pdf
iSCSI , NAS and IP Storage Configuration for Vmware ESX Server - http://download3.vmware.com/vmworld/2006/tac9722.pdf
Starter Edition only supports local storage, and NFS.
You could use iSCSI from within a guest..
Why don't you just add local storage ? You mentioned that you have maxed out your server config ? Assuming it is local SCSI/SAS storage you can add more disks/arrays to that config (either through open bays or external attachment).
If that is not possible than NFS would be your other option (which requires an additional NFS server if you don't have it etc etc).
Massimo.