topic Re: initrd in Operating System - Linux

initrd

Chakravarthi — Thu, 29 Sep 2005 05:34:14 GMT

is there any way to check the contents of .initrd file??

Re: initrd

Slawomir Gora — Thu, 29 Sep 2005 05:46:04 GMT

Hi,

I am not sure you are asking about /boot/initrd.gz file ?

on my system I can:
cd /tmp
cp /boot/initrd_2.6.11-mm1.gz
gzip -d initrd_2.6.11-mm1.gz
mount -o loop /tmp/initrd_2.6.11-mm1 /mnt/

replace you initrd file name with my initrd_2.6.11-mm1.gz

Re: initrd

Chakravarthi — Thu, 29 Sep 2005 07:11:36 GMT

file what i'm taking about is xx.initrd

it is not a bz or tgz file

file returns it is data file

Re: initrd

Slawomir Gora — Thu, 29 Sep 2005 07:41:42 GMT

Hi,
did you try this ?

mount -o loop xx.initrd /mnt/

Re: initrd

Gopi Sekar — Thu, 29 Sep 2005 08:24:48 GMT

if it shows as data file then it is more likely that it is not having any filesystem in it, there is no point in trying to mount it in -oloop method.

I think the name initrd is given just to confuse you. Which application is creating file by this extension?

FYI: If the initrd contains the filesystem then when you put 'file ' then it should give something like 'Linux rev 1.0 ext2 filesystem data'

Hope this helps,
Gopi

Re: initrd

Chakravarthi — Fri, 30 Sep 2005 00:41:43 GMT

when i try mounting using -o loop option it gives the following error message

mount: you must specify the filesystem type

Re: initrd

Gopi Sekar — Fri, 30 Sep 2005 01:10:21 GMT

So it clearly means that you are trying to mount a file which is not having any file system in it, the name initrd is given just to confuse you.

Which application is using this type of file?

Regards,
Gopi

Re: initrd

Stuart Browne — Fri, 30 Sep 2005 06:50:59 GMT

Generally an 'initrd' image is compressed, even if it doesn't have a '.gz' extension.

To check, you can use the 'file' command:

file initrd-2.4.22-1.2199.5.legacy.nptl.img
initrd-2.4.22-1.2199.5.legacy.nptl.img: gzip compressed data, from Unix, max compression

(this is on my fedora-core-1 machine).

The instructions Slawomir were pretty close.

So, either rename it to .gz, then uncompress it, or do it in pipes:

gzip -cd < initrd.img > loop-mount.img
mount -oloop loop-mount /mnt

and away you go.

Re: initrd

Mark Kounalis — Mon, 17 Oct 2005 00:37:01 GMT

The way initrd stores it's information has changed. It's stored in a cpio file now - so after you uncompress the file you need to do a cpio -t < <> to see the contents.