Differences

This shows you the differences between two versions of the page.

--- linux:crash_recovery [2015/12/02 16:58]
tkilla
+++ linux:crash_recovery [2022/07/10 02:03]
tkilla
@@ Line 51: / Line 51: @@
 After restore, click "netboot" in webmanager again and reset it to "harddisc"
+===== Full Disc Encrypted System Rescue =====
+If the system does not boot anymore, **you can open the encrypted device anyway with a live system** on USB stick or CD.
+  # find the correct partitions:
+  fdisk -l
+  # open the container
+  # "sdb5_crypt" is just an example. **Check what's written in /etc/crypttab - the names must match!**
+  cryptsetup luksOpen /dev/sdXY sdXY_sdb5_crypt
+  # activate the LVM volume group (if you use LVM2):
+  vgchange -ay
+  # find new volume groups in /dev/mapper/ and mount them (maybe it's just root or home, var, ...might be in, too):
+  mount /dev/mapper/ubuntu--vg-root /mnt
+  # mount the unencrypted boot parti:
+  mount /dev/sdXZ /mnt/boot
+  # bind mount some important dirs:
+  mount -t proc proc /mnt/proc
+  mount -o bind /dev /mnt/dev
+  mount -t sysfs none /mnt/sys
+Now you can take your data back already.
+To repair what is broken, you probably need to change root into that system:
+  chroot /mnt
+All following commands are executed inside the broken system. Some hints for repairs:
+  apt install lvm2 cryptsetup-initramfs    # debian uninstalled lvm during an upgrade :(
+If your root system is BTRFS, you need btrfs-progs and the kernel module during the early initramfs boot stage:
+  apt install btrfs-progs
+Add a missing module to initramfs - inside the chroot:
+  mcedit /etc/initramfs-tools/modules
+Write one module name like "btrfs" per line.
+Then regenerate the initramfs for all installed kernels:
+  update-initramfs -u -k all
+Also check the UUID entries in /etc/crypttab compared to ls -la /dev/disk/by-uuid/
+TbC..  There may be various other reasons for bootproblems...
+== Links: ==
+  * really helpul! https://feeding.cloud.geek.nz/posts/recovering-from-unbootable-ubuntu-encrypted-lvm-root-partition/
+  * various other hints https://askubuntu.com/questions/567730/gave-up-waiting-for-root-device-ubuntu-vg-root-doesnt-exist#567897

fr33.info

User Tools

Site Tools

Differences

Page Tools