How to check initrd's contents? (was: Re: Disk I/O as a bottleneck?)

[Yedidyah Bar-David]

On Mon, May 09, 2011 at 03:18:08PM +0300, Omer Zak wrote:
> My kernel is configured to have AHCI as a module:
> CONFIG_SATA_AHCI=m
> 
> However I understand that it means that this module is needed also in
> the initrd image.  How can I check which modules made it to the initrd
> image last time it was rebuilt?

something like

mkdir /some/temp/dir
cd /some/temp/dir
gzip -dc < /boot/my-initrd | cpio -idm

That is, assuming it's a ramfs-based initrd and not an old-style
filesystem image.
-- 
Didi