Comment 7 for bug 1167617

I can confirm the same issues as Adrian, with a slightly different use case.

I have Kubuntu 15.04 installed on a USB3 stick (full os, not a livecd). When the BIOS is set to DISABLE USB3 mode I can boot from this fine as per the UEFI entry. UEFI loads the efi copy of Grub, and grub search_fs finds the USB stick partition's uuid and chainloads usb grub further.

However when the BIOS is set to USB3 mode, the stick can only be booted from this entry once. Future attempts to boot the stick result in UEFI loading local EFI grub, however grubs search_fs then fails to find the USB3 stick.

Similarly, USB3 install media, such as the Kubuntu installer, do not appear on the UEFI boot selection screen after this point either.

Booting into Windows from the SSD, loading up vmware with boot-repair-disk with the USB stick passed through, and then performing a repair of the bootloader on the stick... will allow the USB stick to boot precisely one more time. On next restart however it will be back to efi grub failing to find the stick. I can repeat the repair to load as many times as needed.

At this point, my suspicion is the BIOS has problems with USB3 devices.