I hit the problem as well upgrading from 13.10 to 14.04. Quite a shock. -0- After several tries, I finally got it to do an initial boot using "boot from EFI file" (see details below), but then made two changes, after which it kept rebooting OK without intervention, so not sure which of the two changes was critical. The two changes were: -1- sudo dpkg-reconfigure grub-efi-amd64 as suggested by olly_b in #130 (thanks, Olly) -2- in my /boot/efi, moved all subdirectories to /boot/efi/old sudo mkdir /boot/efi/old sudo mv Boot EFI Microsoft ubuntu /boot/efi/old/. and then did sudo mkdir /boot/efi/EFI sudo cp -r /boot/efi/old/EFI/ubuntu /boot/efi/EFI/. More details: My configuration: On a 2012 HP Envy 6 notebook. It's a dual boot setup: Windows 8.1 Update, using 500GB and 32GB internal drives and Ubuntu set up on a 31.6GB external USB flash drive as an encrypted physical volume /dev/sdc3 with the root file system and swap being on logical volumes. It boots from EFI with /dev/sdc2 being mounted at /boot and /dev/sdc1 at /boot/efi. --- $ sudo parted -l Model: ATA Hitachi HTS54505 (scsi) Disk /dev/sda: 500GB Sector size (logical/physical): 512B/4096B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 210MB 209MB primary ntfs boot 2 210MB 479GB 479GB primary ntfs 3 479GB 500GB 21.0GB primary ntfs 4 500GB 500GB 113MB primary fat32 lba Model: ATA SAMSUNG MZMPC032 (scsi) Disk /dev/sdb: 32.0GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 1049kB 8589MB 8588MB primary Model: USB Flash Drive (scsi) Disk /dev/sdc: 31.6GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 512MB 511MB fat32 boot 2 512MB 768MB 256MB ext2 3 768MB 31.6GB 30.9GB Model: Linux device-mapper (linear) (dm) Disk /dev/mapper/ubuntu--vg-root: 22.4GB Sector size (logical/physical): 512B/512B Partition Table: loop Number Start End Size File system Flags 1 0.00B 22.4GB 22.4GB ext4 Model: Linux device-mapper (linear) (dm) Disk /dev/mapper/ubuntu--vg-swap_1: 8485MB Sector size (logical/physical): 512B/512B Partition Table: loop Number Start End Size File system Flags 1 0.00B 8485MB 8485MB linux-swap(v1) Error: /dev/mapper/sdc3_crypt: unrecognised disk label --- Having an EFI boot setup, I should have run "sudo debconf-show grub-efi-amd64" but didn't before I fixed the problem. Anyway, this is how it looks now: --- $ sudo debconf-show grub-pc grub2/kfreebsd_cmdline_default: quiet splash grub-pc/postrm_purge_boot_grub: false grub-pc/install_devices_disks_changed: grub2/device_map_regenerated: grub-pc/hidden_timeout: true grub-pc/install_devices: grub-pc/mixed_legacy_and_grub2: true grub-pc/install_devices_failed_upgrade: true grub-pc/disk_description: * grub2/linux_cmdline_default: quiet splash grub-pc/timeout: 10 grub-pc/chainload_from_menu.lst: true * grub2/linux_cmdline: grub-pc/kopt_extracted: false grub-pc/install_devices_empty: false grub-pc/partition_description: grub-pc/install_devices_failed: false grub2/kfreebsd_cmdline: $ sudo debconf-show grub-efi $ sudo debconf-show grub-efi-amd64 * grub2/linux_cmdline_default: quiet splash grub2/kfreebsd_cmdline: grub2/kfreebsd_cmdline_default: quiet splash * grub2/linux_cmdline: grub2/device_map_regenerated: --- And again, I should have run "sudo efibootmgr -v" before but didn't and here is how it looks now: --- $ sudo efibootmgr -v BootCurrent: 0003 Timeout: 0 seconds BootOrder: 3003,2001,2002,2003 Boot0000* Notebook Hard Drive BIOS(2,0,18)....................................................................... Boot0001* USB Hard Drive - USB Flash Drive BIOS(7,500,53)....................................................................... Boot0003* ubuntu HD(1,800,f3800,3907ec83-43d5-47ee-99bd-5c58abb58abc)File(\EFI\ubuntu\grubx64.efi) Boot2001* USB Drive (UEFI) RC Boot3003* Internal Hard Disk or Solid State Disk RC --- -0- Getting it to boot initially after power on, at prompt "Press ESC key for startup menu", press to interrupt boot F9 to select "boot device options" selected "boot from EFI file" selected first device: ...Usb(0,0)/Usb(1,0)/HD(Part1... roamed around /boot/efi until I found the subdirectory EFI/ubuntu with grubx64.efi and shimx64.efi, then selected the grubx64.efi to boot from. Current Contents of /boot/efi $ ls -lR /boot/efi /boot/efi: total 12 drwxr-xr-x 3 root root 4096 May 2 09:08 EFI drwxr-xr-x 6 root root 4096 May 2 09:07 old drwxr-xr-x 2 root root 4096 Mar 12 12:22 System Volume Information /boot/efi/EFI: total 4 drwxr-xr-x 2 root root 4096 May 2 09:08 ubuntu /boot/efi/EFI/ubuntu: total 1448 -rwxr-xr-x 1 root root 120 Nov 1 02:57 grub.cfg -rwxr-xr-x 1 root root 119296 May 2 09:04 grubx64.efi -rwxr-xr-x 1 root root 1355656 Nov 1 02:57 shimx64.efi /boot/efi/old: total 16 drwxr-xr-x 2 root root 4096 Nov 1 16:05 Boot drwxr-xr-x 5 root root 4096 Nov 1 16:05 EFI drwxr-xr-x 3 root root 4096 Nov 1 16:05 Microsoft drwxr-xr-x 2 root root 4096 Nov 1 16:05 ubuntu /boot/efi/old/Boot: total 128 -rwxr-xr-x 1 root root 127488 Nov 1 16:05 bootx64.efi -rwxr-xr-x 1 root root 0 Nov 1 16:05 bootx64.efi.grb /boot/efi/old/EFI: total 12 drwxr-xr-x 2 root root 4096 Nov 1 16:05 Boot drwxr-xr-x 3 root root 4096 Nov 1 16:05 Microsoft drwxr-xr-x 2 root root 4096 Nov 1 02:57 ubuntu /boot/efi/old/EFI/Boot: total 128 -rwxr-xr-x 1 root root 127488 Nov 1 16:05 bootx64.efi -rwxr-xr-x 1 root root 0 Nov 1 16:05 bootx64.efi.grb /boot/efi/old/EFI/Microsoft: total 4 drwxr-xr-x 2 root root 4096 Nov 1 16:05 Boot /boot/efi/old/EFI/Microsoft/Boot: total 256 -rwxr-xr-x 1 root root 127488 Nov 1 16:05 bootmgfw.efi -rwxr-xr-x 1 root root 0 Nov 1 16:05 bootmgfw.efi.grb -rwxr-xr-x 1 root root 127488 Nov 1 16:05 bootx64.efi -rwxr-xr-x 1 root root 0 Nov 1 16:05 bootx64.efi.grb /boot/efi/old/EFI/ubuntu: total 1448 -rwxr-xr-x 1 root root 120 Nov 1 02:57 grub.cfg -rwxr-xr-x 1 root root 119296 May 2 09:04 grubx64.efi -rwxr-xr-x 1 root root 1355656 Nov 1 02:57 shimx64.efi /boot/efi/old/Microsoft: total 4 drwxr-xr-x 2 root root 4096 Nov 1 16:05 Boot /boot/efi/old/Microsoft/Boot: total 256 -rwxr-xr-x 1 root root 127488 Nov 1 16:05 bootmgfw.efi -rwxr-xr-x 1 root root 0 Nov 1 16:05 bootmgfw.efi.grb -rwxr-xr-x 1 root root 127488 Nov 1 16:05 bootx64.efi -rwxr-xr-x 1 root root 0 Nov 1 16:05 bootx64.efi.grb /boot/efi/old/ubuntu: total 128 -rwxr-xr-x 1 root root 127488 Nov 1 16:05 grubx64.efi /boot/efi/System Volume Information: total 4 -rwxr-xr-x 1 root root 76 Mar 12 12:22 IndexerVolumeGuid You can see there were lots of *.efi files dated Nov 1 [2013] 16:05 with file size 127488 bytes. "cmp" confirmed these were all the same file. However, in the /boot/efi/EFI/ubuntu directory the .efi file was (initially) dated Apr 30 [2014] (the date I did the 13.10 to 14.04 upgrade) and had a different size, 119296 bytes. After I did the "sudo dpkg-reconfigure grub-efi-amd64" this changed date to May 2 [2014] (today's date), and still 119296 bytes in size. So the idea of renaming all the /boot/efi directories into /boot/efi/old, was to get them out of the way so nothing would try to boot them and then moving the EFI/ubuntu directory back to /boot/efi/EFI/ubuntu so there would be only one efi file to pick up and boot from. [I assume at some stage in the past I've done a "boot repair" and it duplicated all the EFI files.] As I say, I'm not sure whether the "sudo dpkg-reconfigure grub-efi-amd64" or the renaming of the /boot/efi subdirectories fixed the problem, but I'm rebooting OK now without any manual intervention.