"Otherwise the following are supported: DAS, NAS, SAN and boot from SAN (diskless) with NFS, FC, iSCSI and FCoE transport options. Note that diskless servers are only supported if all UC apps on the physical server / ESXi host support both vSphere ESXi 4.1 and the VMware "boot from SAN" feature (see the VMware Requirements page)."
ESXi 4.1 support le boot sur USB ou SD, du coup les appliances cisco suivent ... enfin ce n'est que ma compréhension personnelle !
http://kb.vmware.com/selfservice/m [...] Id=1020655