Troubleshooting

GRUB CryptFS Password Typo

Unlocked CryptFS on GRUB boot will stall if mistyping the password. Restart the unlock and boot process without restarting:

cryptomount -a
insmod normal
normal

Remote Dropbear/Wireguard/CryptFS Rescue from Bad Upgrade

System does not boot after a dist-upgrade but Dropbear connects over wireguard.

Connect via Dropbear and Manually Mount Drive

# Remote unlock as normal.
ssh -i ~/.ssh/dropbear root@172.31.255.11

# Open LUKS encrypted disk.
cryptsetup luksOpen /dev/nvme0n1p3 luks

# Find mapped device.
ls /dev/mapper
> /dev/mapper/b--vg-root ../dm-1

# Mount drive for changes.
mkdir /mnt
mount -t ext4 /dev/dm-1 /mnt

# Make changes also chroot if needed.

Umount and reboot

umount /mnt
rmdir /mnt
cryptsetup luksClose /dev/mapper/b--vg-root
cryptsetup luksClose /dev/mapper/b--vg-swap-1
cryptsetup luksClose /dev/mapper/luks

reboot -f

Grub OS Prober

Grub will throw the following error on 4.9+ Kernels running VM's on block devices or ZFS during normal upgrades:

device-mapper reload ioctl on osprober-linux

These devices are attempted to be unmounted while in use to detect other OS's on those partitions. This may be safely disabled if you are only running one OS.

/etc/default/grub

0644 root:root

GRUB_DISABLE_OS_PROBER=true

update-grub
apt update && apt upgrade
reboot

Reducing Disk Writes

Minimize disk writes to SSD devices to increase longevity.