Warning message from ' initramfs-tools configuration sets RESUME '

cf: https://ubuntuforums.org/showthread.php?t=2401012

 

The following warning message comes out while update-grub.

update-initramfs: Generating /boot/initrd.img-4.15.0-134-generic
W: initramfs-tools configuration sets RESUME=UUID=970f542b-b717-470e-aaf1-f9b7de0d017e
W: but no matching swap device is available.

Then, do this:

1. Find the swap UUID by lsblk, say
   nvme0n1p5 259:5    0   1.1G  0 part [SWAP]
2. Find UUID by
   sudo blkid /dev/nvme0n1p5
   say,
   /dev/nvme0n1p5: UUID="daa5df9d-4f1d-49cd-9bf8-54befb294691" TYPE="swap" PARTUUID="526d72e6-e43a-492a-bb48-61e361598817"
3. Replace the UUID with the one shown in the above in /etc/initramfs-tools/conf.d/resume
4. ATTENTION!! DO NOT save the old resume, e.g. cp it as resume_old. The dir /etc/initramfs-tools/conf.d/ cannot have more than 1 file.
5. Then,
   sudo update-grub
   or
   sudo update-initramfs -u -k all