after more googling:

this is new since fc3 and the correct command to recreate the initrd is
cd /path/to/patched/dir
find . |cpio -o -H newc|gzip > newinitrd.img

and it works ;)

stijn

Stijn De Weirdt wrote:
> hi all,
> 
> cpio -i seems to extract it.
> can someone confirm that this is the new style for initrd?
> (googling didn't reveal much. using file i found out it was cpio ;)
> 
> stijn
> 
> 
>> b. we are missing a scsi driver (for 3ware 9650) in the pxe initrd, so 
>> i'm trying to add it (done this before.)
>>
>> but know i get stuck in the very first step:
>> afterdownloading initrd.img, gunzipping it, i try to mount it and i 
>> get the following error:
>> mount: you must specify the filesystem type
>>
>> explicitly trying ext2 (and even ext3) it still fails.
>> i tried it with and sl45 initrd.img file and there it worked without 
>> any problem.
>>
>> any hints on how to get it working?
>>
>> stijn
>>
>