GRUB Rescue
When being forced into GRUB rescue mode, run ls and ls <one_partition> to check available partitions and find the one that we should boot from [ref].
Then set prefix & root [ref]:
set root=(hdX,Y)
set prefix=(hdX,Y)/boot/grub
insmod normal
normal
To avoid doing this every time, it is recommened to use a live-USB/ISO to repair GRUB (usually only Desktop version can be in live-USB and easy to setup WIFI). (// it should be also ok to do this without USB if there is a nix system working on current HDD).
Then use boot-repair to repair the grub.
sudo add-apt-repository ppa:yannubuntu/boot-repair && \
sudo apt-get update && \
sudo apt-get install -y boot-repair && \
boot-repair
It will automatically repair it.
System backup #
eg1 to a file:
dd status=progress bs=100M iflag=fullblock if=/dev/sda | lbzip2 > /home/sda.img.bz2
Note, status=progress requires Ubuntu 16.04 or newer.
askubuntu
computerHope
fullblock
eg2 to another disk/partition:
dd if=/dev/sda of=/dev/sdb & pid=$!
# or:
dd if=/dev/sda of=/dev/sdb 2>>/home/file.txt & pid=$!
watch -n 10 kill -USR1 $pid
WARN: USR1 for Linux, SIGINFO for OSX (USR1 will still kill the pid in OSX).
