Kernel Panic - not syncing: VFS: Unable to mount root fs on

VFS

https://askubuntu.com/questions/895492/kernel-panic-vfs-cannot-open-root-device-or-unknown-block-error-6

sudo update-initramfs -u -k $(uname -r)

https://askubuntu.com/questions/41930/kernel-panic-not-syncing-vfs-unable-to-mount-root-fs-on-unknown-block0-0

sudo fdisk -l
sudo mount /dev/sda2 /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /dev/pts /mnt/dev/pts
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo chroot /mnt

sudo mount /dev/sday /mnt/boot

update-initramfs -u -k 5.4.0-99-generic

dpkg --list | grep linux-image

update-grub

https://unix.stackexchange.com/questions/698890/out-of-memory-on-loading-initial-ramdisk-after-kernel-upgrade-4-15-to-4-19-o

vim /etc/initramfs-tools/initramfs.conf

MODULES=dep
COMPRESS=xz

https://unix.stackexchange.com/questions/270390/how-to-reduce-the-size-of-the-initrd-when-compiling-your-kernel

cd /lib/modules/<new_kernel>
find . -name *.ko -exec strip --strip-unneeded {} +