[Fedora-livecd-list] WARNING: Cannot find root file system, when mksiofs from good livecd ISO files ?

[Ed Sutton]

I made an ISO using mkisofs with *unmodified* source files from a known working livecd ISO image.  When I boot the ISO, after waiting 60 seconds, I get the following message, and then it drops to a emergency bash shell:

WARNING: Cannot find root file system!

I assume this is a problem with my mkisofs options, or perhaps the way I copy the files from the mounted ISO.  Here's what I did:

1 - Started with a good bootable livecd ISO.  
2 - Mounted ISO and copied all files 
3 - Without modifying any files, I rebuilt using following mkisofs command

mkisofs -o image/cloned-livecd-i386.iso \
-v \
-R -J -T \
-b isolinux/isolinux.bin \
-c isolinux/boot.cat \
-no-emul-boot \
-boot-load-size 4 \
-boot-info-table \
unmodified-iso-files/.


My eventual goal is to debug why an ISO made using livecd-creator cannot boot with a modified /isolinux/initrd.img containing the /lib/modules/ from an updated kernel.  To simplify the problem, I am trying to recreate an ISO from the source of a known good livecd ISO.  Any tips or suggestions are much appreciated.

Thanks in advance,

-Ed