grub does not start

From time to time – like every quarter – my grub want’s to make me crazy and does not load. How to solve it? Read along!

Using Dell xps15 with ubuntu 17 and win10 uefi dualboot via grub2. Some partitions are encrypted as follows:

$ blkid
# /boot/efi
/dev/nvme0n1p1: LABEL="ESP" UUID="" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID=""
# /boot
/dev/nvme0n1p11: LABEL="boot_ubuntu" UUID=" TYPE="ext4" PARTLABEL="boot_ubuntu" PARTUUID=""
# ubu (crypt)
/dev/nvme0n1p10: UUID="" TYPE="crypto_LUKS" PARTUUID=""
# mapped (after luksOpen)
/dev/mapper/ubu_crypt: UUID="" TYPE="ext4" = 10

# srv_crypt
/dev/nvme0n1p6: UUID="" TYPE="crypto_LUKS" PARTUUID=""
# home_crypt
/dev/nvme0n1p7: UUID="" TYPE="crypto_LUKS" PARTUUID=""
# live usb
/dev/sda1: LABEL="UBUNTU 16_0" UUID="" TYPE="vfat" PARTUUID=""
/dev/loop0: TYPE="squashfs"
# other-legacy-etc
/dev/nvme0n1: PTUUID="" PTTYPE="gpt"
/dev/nvme0n1p2: PARTLABEL="Microsoft reserved partition" PARTUUID=""
/dev/nvme0n1p8: UUID="" TYPE="crypto_LUKS" PARTUUID=""
/dev/nvme0n1p12: LABEL="WINRETOOLS" UUID="" TYPE="ntfs" PARTUUID=""
/dev/nvme0n1p13: LABEL="Image" UUID="" TYPE="ntfs" PARTUUID=""
/dev/nvme0n1p3: LABEL="OS" UUID="" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID=""
/dev/nvme0n1p4: UUID="" TYPE="ext4" PARTUUID=""
/dev/nvme0n1p5: LABEL="datasss" UUID="" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID=""
/dev/nvme0n1p9: LABEL="DaTa" UUID="" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID=""

quick story

  • boot into live ubuntu usb
  • mount crypt partitions
  • mount other partitions
  • chroot into system
  • run grub install (mkconfig) to reinstal grub to the selected disk (not partition but disk)
  • update-grub (finds the loadable OSes kernels – linux and win)
  • check fstab and crypttab
  • check other-then-root crypt partition mounting
  • initramfs-update (generate the grub menu)
  • config BIOS
  • errata
export DISK_FOR_GRUB='/dev/nvme0n1'
export PART_UBU='/dev/nvme0n1p10'
export PART_BOOT='/dev/nvme0n1p11'
export PART_BOOT_EFI='/dev/nvme0n1p1'
export CRYPT_ALIAS_UBU='ubu'

# (OPT)
export PART_HOME='/dev/nvme0n1p7'
export CRYPT_ALIAS_HOME='home_crypt'

# be able to mount encrypted ubu partition
sudo modprobe dm-crypt
sudo cryptsetup luksOpen $PART_UBU $CRYPT_ALIAS_UBU
# insert the code of the crypt partition

# the $CRYPT_ALIAS_UBU is then in /etc/fstab and also /etc/crypttab
sudo mkdir /mnt /mnt/boot /mnt/boot/efi
sudo mount /dev/mapper/$CRYPT_ALIAS_UBU /mnt
sudo mount $PART_BOOT /mnt/boot
sudo mount $PART_BOOT_EFI /mnt/boot/efi

# mount the live-ubuntu folders to your mounted ubuntu dir
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
# chroot into the ubuntu install
sudo chroot /mnt

# fill these from your upper choice
export CRYPT_ALIAS_UBU='ubu_crypt'  
# (OPT)
export CRYPT_ALIAS_HOME='home_crypt'

# install grub to the disk (not partition, but disk - no p# suffix)
grub-install $DISK_FOR_GRUB

# (opt) make a backup of your system fstab and crypttab
cp /etc/fstab /etc/fstab_orig
cp /etc/crypttab /etc/crypttab_orig

# (opt) copy the info about mounted
# cp /proc/mounts /etc/mtab  # all now mounted disks should be remounted on startup?

# let it find the distros on the mounted /boot partition - recreate config
# both are the same:
# grub-mkconfig -o /boot/grub/grub.cfg

# if you got some /boot/efi Input/output error you can correct the possibly corrupted partitions
sudo fsck -p -f -C0 $PART_BOOT_EFI
# and rerun the update-grub

# it should output the kernels found!
# - if not something is wrong 
# - make sure you `cp /proc/mounts`
# or try: `grep -v rootfs /proc/mounts > /etc/mtab` - if your boot is on the same parition as ubuntu install
# - make sure you mounte the boot partition if it's separate

# check wheather you have the same crypt partition names as your aliases
# you used for their luksOpen - they must be the same as the ones in 
# /etc/fstab and /etc/crypttab
cat /etc/crypttab | grep $CRYPT_ALIAS_UBU
cat /etc/fstab | grep $CRYPT_ALIAS_UBU

# (OPT)
cat /etc/crypttab | grep $CRYPT_ALIAS_HOME
cat /etc/fstab | grep $CRYPT_ALIAS_HOME

# they also have to have the correct UUID and setup..
# fstab example:
/dev/mapper/ubu / ext4 rw,relatime,data=ordered 0 1
# crypttab example:
ubu_crypt UUID=xxx none luks,discard
# also add all the other partitions which you would like to mount on start

# update-initramfs 
update-initramfs -u -k all

# if it outputed lines like the following, containing all your wanted kernels you should be fine
# > update-initramfs: Generating /boot/initrd.img-4.13.0-36-generic

# CHECK other-then-root crypt partitions mounting
# as you are chrooted using your root partition $PART_UBU you cannot test the mounting of it
# however, you can test mounting of other crypt partitions - test your fstab and crypttab config

sudo cryptdisks_start $CRYPT_ALIAS_HOME 

# normal output:
 * Starting crypto disk... 
 * home_crypt (starting)..
Please unlock disk home_crypt: 
 * home_crypt (started)... 

# exit and umount
sudo umount /mnt/boot /mnt/dev /mnt/proc /mnt/sys /mnt

# restart
sudo reboot -n

# BIOS setup UEFI boot option
Maybe you need to add the option in UEFI bios - advanced booting options
Dell xps15 
select disk: FS0
go to boot /efi/grub find shim.efi
name it: ubuntu
click add

select to defaultly boot from this

if the login holds after you successfully input the crypttab partition code
it may be because some old CRYPT_ALIAS has made it's way into the grub boot option
manually edit the grub boot line before Enter press e on the selected boot option in grub menu
check whether the `load`... line has the correct /dev/mapper/$CRYPT_ALIAS_NAME
rewrite it and press `ctrl+x`

If this happen:

FUCK the fstab was overwritten
maybe the crypttab also
- ok added the backup commands into the tutor - you can recreate them from the backup

## otherwise recreate them manually
Automount a luks encrypted volume on system start
### /etc/crypttab ``` sudo cryptsetup luksDump /dev/nvme0n1p6 | grep "UUID" >> /etc/crypttab sudo cryptsetup luksDump /dev/nvme0n1p7 | grep "UUID" >> /etc/crypttab ``` edit the file: ``` sudo vim /etc/crypttab ``` add the label = to the uuids ``` home_crypt UUID=<uuid> none luks srv_crypt UUID=<uuid> none luks ``` try loading ``` sudo cryptdisks_start home_crypt ``` ### /etc/fstab ``` /dev/mapper/home_crypt /home ext4 rw,relatime 0 2 ```



if you get something like

initramfs-tools configuration sets RESUME=/dev/mapper/swap_crypt

check your /etc/initramfs-tools/*


cd /etc/initramfs-tools



and change it to your liking





# well then

we meet again when my kernel stopped booting

got error

during `update-initramfs -u -k 4.4`

WARNING: missing /lib/modules/4.4
Ensure all necessary drivers are built into the linux image
depmod: ERROR: could not open directory /lib/modules/4.4: No such file or directory
depmod: FATAL: could not search modules: No such file or directory
depmod: WARNING: could not open /var/tmp/mkinitramfs_IQZ8LU/lib/modules/4.4/moudles.order: No such file or directory
depmod: WARNING: could not open /var/tmp/mkinitramfs_IQZ8LU/lib/modules/4.4/moudles.builtin: No such file or directory

> apt autoremove -s

will be REMOVED:
linux-image-extra-4.4.0-97-generic linux-signed-image-4.4.0-97-generic


issue on askubuntu =

## possible causes

received sigrtmin+21 from plymouthd

driver ath10k_pci – from spinup ubuntu probably – not found on startup


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