Gluster 3.1 FAQ: I prepared the USB image, but it doesn't boot on my machine?
From GlusterDocumentation
Check if your BIOS supports a USB boot disk. If it does, please enable it in the BIOS for your system. Then reboot your system.
Check if your BIOS supports a USB boot disk. If it does, please enable it in the BIOS for your system. Then reboot your system.