Não é possível atualizar o kernel Ubuntu 16.04

Question

Estou tentando atualizar o kernel em um VPS para 4.8 (ou 4.8.X), mas por alguma razão ele está ignorando o grub ou algo mais está acontecendo.

uname -a produz Linux vlanp 2.6.32-042stab120.6 #1 SMP Thu Oct 27 16:59:03 MSK 2016 x86_64 x86_64 x86_64 GNU/Linux

Eu segui as instruções na página seguinte: link e executando o comando dpkg --list | grep linux-image lista como instalado:

ii  linux-image-4.6.0-040600-generic           4.6.0-040600.201606100558                     amd64        Linux kernel image for version 4.6.0 on 64 bit x86 SMP
ii  linux-image-4.6.0-040600-lowlatency        4.6.0-040600.201606100558                     amd64        Linux kernel image for version 4.6.0 on 64 bit x86 SMP
ii  linux-image-4.8.0-040800-generic           4.8.0-040800.201610022031                     amd64        Linux kernel image for version 4.8.0 on 64 bit x86 SMP
rc  linux-image-4.8.10-040810-generic          4.8.10-040810.201611210531                    amd64        Linux kernel image for version 4.8.10 on 64 bit x86 SMP

Eu tentei reiniciar usando grub-reboot <number> para tentar fazer o kernel inicializar pelo menos uma vez, mas ele reinicializa em 2.6 toda vez.

• Não há /etc/default/grub file
• Não há /boot/grub/grub.cfg file

Aqui está a lista do kernel de /boot/grub/menu.lst :

title           Ubuntu 16.04.1 LTS, kernel 4.8.0-040800-generic
root            (hd0,0)
kernel          /boot/vmlinuz-4.8.0-040800-generic root=/dev/hda1 ro quiet splash
initrd          /boot/initrd.img-4.8.0-040800-generic

title           Ubuntu 16.04.1 LTS, kernel 4.8.0-040800-generic (recovery mode)
root            (hd0,0)
kernel          /boot/vmlinuz-4.8.0-040800-generic root=/dev/hda1 ro  single
initrd          /boot/initrd.img-4.8.0-040800-generic

title           Ubuntu 16.04.1 LTS, kernel 4.6.0-040600-lowlatency
root            (hd0,0)
kernel          /boot/vmlinuz-4.6.0-040600-lowlatency root=/dev/hda1 ro quiet splash
initrd          /boot/initrd.img-4.6.0-040600-lowlatency

title           Ubuntu 16.04.1 LTS, kernel 4.6.0-040600-lowlatency (recovery mode)
root            (hd0,0)
kernel          /boot/vmlinuz-4.6.0-040600-lowlatency root=/dev/hda1 ro  single
initrd          /boot/initrd.img-4.6.0-040600-lowlatency

title           Ubuntu 16.04.1 LTS, kernel 4.6.0-040600-generic
root            (hd0,0)
kernel          /boot/vmlinuz-4.6.0-040600-generic root=/dev/hda1 ro quiet splash
initrd          /boot/initrd.img-4.6.0-040600-generic

title           Ubuntu 16.04.1 LTS, kernel 4.6.0-040600-generic (recovery mode)
root            (hd0,0)
kernel          /boot/vmlinuz-4.6.0-040600-generic root=/dev/hda1 ro  single
initrd          /boot/initrd.img-4.6.0-040600-generic

title           Ubuntu 16.04.1 LTS, memtest86+
root            (hd0,0)
kernel          /boot/memtest86+.bin