Boot

OS : Ubuntu 18.04

Grub

GRand Unified Bootloader

Kernel params can be passed using the following in

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash NAME=VALUE”

Resume after hibernate

Use resume=UUID=0b784ace-b11c-4e78-9a90-e4601d6a03c0

Where the UUID points to to the swap disk.

initramfs

“Once the Linux kernel has control over the system (which it gets after being loaded by the boot loader), it prepares its memory structures and drivers. It then hands over control to an application (usually init) whose task it is to further prepare the system and make sure that, at the end of the boot process, all necessary services are running and the user is able to log on…” Initramfs Guid - Linux boot process

If grub is configured to resume from e.g. UUID=0b784ace-b11c-4e78-9a90-e4601d6a03c0, then initramfs must be configured to resume from the same. This doesn’t have to be configured explicitly as update-initramfs figures it out automatically:

sudo update-initramfs -u -k all

I: The initramfs will attempt to resume from /dev/nvme0n1p3
I: (UUID=0b784ace-b11c-4e78-9a90-e4601d6a03c0)
I: Set the RESUME variable to override this.

However, to avoid this message, you can create a file with the contents:

cat /etc/initramfs-tools/conf.d/resume && \
echo RESUME=UUID=0b784ace-b11c-4e78-9a90-e4601d6a03c0 | sudo tee /etc/initramfs-tools/conf.d/resume

sudo update-initramfs -u -k all