Hello, Centos 7.x Let say a clean-install of Centos 7.x is being performed on a box simply with two partitions / and /boot ... and that there is no extra complexity like lvm , raid ,etc,etc ... Centos 7.x process allows / to be encrypted with pass phrase... How can a key, residing on a usb flash drive, to be added to the encryption of / ? So the system needs both manual input of pass phrase as well as presence of usb flash drive to come up after getting rebooted. Thank you, F-