Karmic 9.10: cannot uncompress initrd.lz

First of all, it's "/initrd.gz", not "/initrd.lz". Why are you trying to uncompress this anyway? This is an important system file for linux and is handled internally by the kernel. You shouldn't have a need to touch it.

1) Karmic 9.10 use initrd.lz instead of initrd.gz
2) I need to change some casper init scripts in a live-cd context

I found a solution by myself!

1) Install p7zip-full via synaptic package manager
2) Create a subdirectory to preserve the init subdirectory tree
3) Decompress initrd.lz with "7z e -so ../initrd.lz | cpio -id"

To compress it again go to the init subdirectory and execute:
4) find | cpio -o -H newc > ../newinitrd
5) go up one directory
6) 7z a -m0=lzma:a=1 initrd-mod.lz newinitrd

See comment above

To uncompress and

gunzip < initrd.gz | cpio -i

and then to recompress I'd use:

find . | cpio -o -H newc | gzip -9 > newinitrd.gz

Hi Colin,

thx for your reply. Indeed your statements are right for Jaunty not for Karmic.