Comment 95 for bug 1842320

Earlier today, I upgraded my Mint 20.3 system to Mint 21.0 and got this "out of memory" issue (Asus ROG G752VT laptop.).

The fix in comment #41 and #89 worked (changing the compression to 19), but a lot of the steps were not needed.

This is the minimal steps needed, (maybe fewer possible, anybody up for some code golf?):

$ sudo su -
# mkdir root
He probably had his disk encrypted, I do not: # cryptsetup luksOpen /dev/nvme0n1p3 nvme0n1p3_crypt

This one was very different for me due to mint vs Ubuntu.
# mount /dev/mapper/vgmint-root ./root was # mount /dev/mapper/vgubuntu-root ./root

This one makes the computer think the normal root is really root to fake out update-initramfs:
# chroot ./root

Yes, do this:
# ### Now edit line 196 of /usr/sbin/mkinitramfs to to use -19 instead of -1
This wasn't completely happy with me, but it worked out ok for me.
# update-initramfs -u -k all

This command completely failed for me, but it didn't seem to hate me afterwards:
# update-grub

# exit
# reboot

I hope you have a happy reboot too.

Then re-run
# update-initramfs -u -k all
and
# update-grub

To clean up any oddities.

I wish there were a way to recompress this from grub though.