ubuntu@ubuntu:~$ sudo mount /dev/mapper/ubuntu--vg-root /mnt
ubuntu@ubuntu:~$ sudo mount --bind /dev /mnt/dev
ubuntu@ubuntu:~$ ls /mnt/boot
efi
ubuntu@ubuntu:~$ sudo mount /dev/sda2 /mnt/boot
ubuntu@ubuntu:~$ sudo chroot /mnt

root@ubuntu:/# mount -t proc none /proc
root@ubuntu:/# mount -t sysfs none /sys
root@ubuntu:/# mount -t devpts none /dev/pts
root@ubuntu:/# export HOME=/root
root@ubuntu:/# export LC_ALL=C

root@ubuntu:/# apt-get update
root@ubuntu:/# apt-get -y install linux-image-generic

root@ubuntu:/# umount /proc || umount -lf /proc
root@ubuntu:/# umount /sys /dev/pts
root@ubuntu:/# exit
exit
ubuntu@ubuntu:~$ sudo umount /mnt/dev /mnt

net.core.wmem_max=12582912
net.core.rmem_max=12582912
net.ipv4.tcp_rmem= 10240 87380 12582912
net.ipv4.tcp_wmem= 10240 87380 12582912
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_window_scaling = 0
net.core.netdev_max_backlog = 5000
vm.swappiness=10
vm.dirty_writeback_centisecs = 600