Are you troubleshooting I/O errors of local disks ?
If your conclusion is "something obscure happens in the BIOS of the ESXi-host" then maybe this helps:
Understanding ATA Security » ADMIN Magazine
Symptoms may be:
hexdump -C /dev/disks/t10************:1 - fails immediatly with an I/O error
partedUtil getptbl /dev/disks/t10******************* fails
dd commands fail at once with I/O errors
