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linux:crash_recovery [2015/10/31 19:55]
tkilla 		linux:crash_recovery [2022/07/10 02:07] (current)
tkilla [Full Disc Encrypted System Rescue]
Line 3: Line 3:
 ===== Strato Root Server ===== ===== Strato Root Server =====
  
-Recovery Console:+ 
 +Login to Remote-Console first, so you can see boot messages, ... and kernel panics, if unlucky 
 + 
 +Re-Install takes 1h 
 + 
 +==== Recovery Console: ==== 
  
 Set Boot mode to recovery in "RecoveryManager" at https://config.stratoserver.net/ Set Boot mode to recovery in "RecoveryManager" at https://config.stratoserver.net/
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 To exit the recovery console you need to set boot mode to normal and wait 10min until "ServerData" Serverstatus shows: Installation finished To exit the recovery console you need to set boot mode to normal and wait 10min until "ServerData" Serverstatus shows: Installation finished
 +
 +===== SoYouStart / OVH Root Server =====
 +
 +**You need to setup your ssh key in the webmanager to enter in rescue mode without password!** the password will be sent by mail as well.
 +
 +- Change netboot mode in web-manager: set to "rescue"
 +- Click "reboot"
 +
 +Mount partitions:
 +  mkdir /mnt/md2
 +  mount /dev/md2 /mnt/md2/
 +
 +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
 +
 +
 +* Check that the name in /etc/crypttab is the same as in the cryptsetup luksOpen Command, usually something like sda5_crypt
 +* 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
 +
 +
 +
 +
linux/crash_recovery.1446317733.txt.gz · Last modified: 2015/10/31 19:55 by tkilla

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