@TheBobkin. Thanks. But as I know vSAN ESA is not limited to ready nodes if you want to enable vSAN8 in your environment it is asking which type of vSAN want to use OSA/ESA . So ESA is not limited to readynoed
about second question and disk's type want to know Does it suitable to buy just mixed intensive disk for storage pool when we are using ESA ? (As I said before that in OSA recommendation is to have two types of disk write intensive for cache tier and mixed intensive disks for capacity tier)