[Fedora-livecd-list] livecd-creator proposal for compression option

[Bruno Wolff III]

As part of trying to get the LMZA for Live Images feature
(https://fedoraproject.org/wiki/Features/LZMA_for_Live_Images)
done, I plan on producing a patch soon that provides an option to
livecd-creator to specify a compression type.

The plan is:

Add a new option, --compression_type=string, where string is a compression
type recognized and normally passed to mksquashfs.

Make a default compression type config, that will initially be 'zlib', but
will allow for an easy change to 'lzma', when we are ready.

Make a config that knows the default compression ('zlib') for mksquashfs.
If this string matches the requested compression type, then no compression
option will be passed to mksquashfs. This allows 'zlib' to be used with
older versions of mksquashfs that don't allow for specifying the compressor.

Document at least the 'zlib' and 'lzma' compression types. (And maybe 'lzo'
if that ends up being usable at some point.) Note that 'lzma' needs kernel
support to be able to mount the file system or to use it in live images.

If anyone has suggestions for this plan, making changes now will be less
work than after I have some patches ready.

Thanks.