hello all, I managed to install Esxi 5 on usb flash disk. My question is I have 4 sata harddisks and operate in AHCI mode (BIOS setup). Can I use those harddisk for creating vm?. Is it safe?how about harddisk performance?. Can I use those harddisk also for datastore location?. If in BIOS I setup IDE mode for harddisk controller, can I use those harddisk instead of AHCI mode?What are the limitations if I use sata harddisk?

I'm not sure you'll see much of a difference between running in IDE vs AHCI mode.

You can create a datastore to store your VMs or if you want to allocate an entire disk to a VM, you can use a raw device mapping (RDM) but you still first have to create a datastore to store some pointer files.