Dell POWEREDGE C6105 Hardware Owner's Manual page 46

Option
Hard Disk Drives
CD/DVD Drives
USB Drives
Network Drives
46 | Using the System Setup Program
Description
Specifies the boot device priority sequence from
the available hard drives.
This item only can be seen when system have
bootable Hard Disk Drives.
Specifies the boot device priority sequence from
available CD/DVD Drives.
This item only can be seen when system have
bootable CD/DVD Drives.
Specifies the boot device priority sequence from
available USB Drives.
This item only can be seen when system have
bootable USB Drives.
Specifies the boot device priority sequence from
available Network Drives.
This item only can be seen when system have
bootable Network Drives (PXE).