Viewing compressed fs's

lymae · 12-14-2006, 11:20 AM

Hey

I just want to ask if there's a way to decompress and mount a compressed filesystem as the kernel does after bootload, while already having loaded another distro.

Let's say that I'm already running a LiveDVD Distro *** and I want to view the /boot/initrd.gz in a temporary mount-form so I can take a look at the linuxrc script.

Well, is it a hard one?

nx5000 · 12-14-2006, 11:31 AM

You need to know the format of the file

Depending on the type, you can uncpio or mount it as a loop.

So what type is it:
file /boot/initrd.gz

lymae · 12-14-2006, 12:44 PM

Quote:

Originally Posted by nx5000

So what type is it:
file /boot/initrd.gz

This is what I get:

minirt.gz: gzip compressed data, was "miniroot.img", from Unix, last modified: Sun May 14 23:01:35 2006, max compression

I just realized the name was minirt.gz and not inird.gz, but that's not the point now, is it

And BTW, why are they called loop devices? Do you always need them to mount .img or .iso?

nx5000 · 12-15-2006, 07:08 AM

Arg sorry
file -z /boot/initrdxxx

Some files are just archive. Others are a complete filesystem so you need to create a loop device or dm to see and modify them (isos can be also seen without mounting but can't be modified)

lymae · 12-15-2006, 04:10 PM

Quote:

Originally Posted by nx5000

Arg sorry
file -z /boot/initrdxxx

Some files are just archive. Others are a complete filesystem so you need to create a loop device or dm to see and modify them (isos can be also seen without mounting but can't be modified)

Thanks for the info

nx5000 · 12-18-2006, 07:43 AM

Well, I was about to give you more info if you had given me the result of the command

In case it says cpio archive, you can extract like this:

mkdir /tmp/initrd
cd /tmp/initrd
zcat /boot/initrdxxx | cpio -idv

If its not a cpio archive, then you probably need a loop device. This is explained everywhere on internet.
http://www-128.ibm.com/developerwork.../l-initrd.html