How clean up after update-initramfs -u
 

I'm working on a custom Ubuntu 10.04 live cd, and I've found updating the Plymouth splash uses up a lot more disk space. The culprit seems to be the command update-initramfs -u, which is needed to apply the new splash image. I'm guessing it's making a new intrd image or something. Can anyone help?

yeah, its making a backup img most likely
see if there is a back .img in /boot
I usually use

update-initramfs -u -v -t -k all

is that what you mean?

It did the exact same thing.
I looked in /boot, and there's no initrd.img, but after running either command there's initrd.img-2.6.32-21-generic.

I've got it! Success!

Live CDs don't really have an initrd image in the filesystem. I just had to move it into the casper directory of the disk, name it initrd.lz, and it worked! There was a gain about about 3MB, but that's ok.