Livecd techniques

Lauri Kasanen curaga at
Sun Dec 2 05:20:49 PST 2007


I'm looking into the various livecd techniques, how to pretend r/w, compression..
I just looked at the latest 6.3-min cd. I understood most of it, but have some questions left:

In the past Alexander told me:
> Cloop was never used on LFS LiveCDs. Older CDs used squashfs for
> compression, while modern CDs use zisofs. The change was done because,
> with device-mapper based RW mechanism, one has to compress a single file
> (root.ext2), not a full filesystem tree, and both zisofs and squashfs
> are equally efficient for that - but zisofs is simpler to set up.

Why is this so? There isn't much documentation on device-mapper available..
Why couldn't a squashfs file be used as the first loop device?

2) How did you come up with the overhead calculated?
I guess it's used to have a little bigger writable area than the original even if there's less ram than the livecd size available, correct me if I'm wrong..

3) What's the minimum amount of RAM needed to boot the LFS livecd? By my tries in qemu it's somewhere between 20 and 30mb, as 22 didn't boot and 30 booted. Is this because the 
initramfs file is 15mb uncompressed?

Thanks, Lauri

Surf the Web in a faster, safer and easier way:
Download Opera 9 at

Powered by Outblaze

More information about the livecd mailing list