No space left on device on nixos-rebuild

[Jonah Bron]

I'm encountering an error when running nixos-rebuild on a freshly infected system.

updating GRUB 2 menu...
cannot copy /nix/store/i1i6pn1wz0i25pvwcfhdra4bz6hcqjp7-linux-6.1.74/Image to /boot/kernels/i1i6pn1wz0i25pvwcfhdra4bz6hcqjp7-linux-6.1.74-Image.tmp: No space left on device

It seems that the error originates from the fact that the original system's partition mounted at /boot/efi is later being mounted at /boot. That's not inherently a problem except that it is only 100MB or so, not large enough to hold the entire kernel.

[Jonah Bron]

My workaround is to bind kernels/ to a different drive temporarily when I'm running a rebuild that I know will swap the kernel.

(running as root)

cd
mkdir kernels-tmp
mount --bind kernels-tmp/ /boot/kernels
# nixos-rebuild switch ...
umount /boot/kernels
rm -rf /boot/kernels/*
mv kernels-tmp/* /boot/kernels/
rm -rf kernels-tmp

[Jonah Bron]

I've been able to alleviate this problem even further by ensuring only one kernel version is maintained at a time.

https://search.nixos.org/options?channel=unstable&show=boot.loader.grub.configurationLimit

boot.loader.grub.configurationLimit = 1;

Still not ideal, but I don't have to do the file shuffling workaround anymore.