Remastering DVD -- compression required?

[troburn69]

I've been tinkering w/ creating customized Knoppix images and have been pleased w/ the results. I've successfully created bootable custom CD's and thumbdrives. My real goal however is to create larger custom distributions (3-4 GB expected total filesystem size) that I will deploy on large capacity thumbdrives or DVDs. Here's the question:

Is it required that I use a compressed filesystem? I find that the compression process on my hardware takes 45 minutes to an hour or longer (depending on how large it is and which machine is handling the compression process) and this creates a somewhat painful development loop to test minor changes. One thought I had was to just use a compression level that was not very aggressive but I don't see any options for that on the man page for create_compressed_fs.

Any experience or suggestions on this? All of the HOWTO's I've found don't address this point.

Assuming this can be done (that is, that I can use a non-compressed filesystem) -- are there any reasons that I wouldn't want to do this?

Thanks!

-Andy

[knoppu]

if you dont want to use a compressed fs you will need to change the way it is mounted. For this you will need to look at the outer layer: minirt.gz

loop mount a cd image ; cd /boot ; gzip the minirt.gz ; loop mount minirt ; see what you can do in there.

-- are there any reasons that I wouldn't want to do this?

due to the slow access of optical media it is probably faster to load less data and decompress it than to load uncompressed image.

cloop also provides indexing of the blocks so they can be accessed as required, that may be faster than an uncompressed ISO image.

those arguements concern your final image, not reducing your test cycle.

http://www.knoppix.net/wiki/Cloop#Creating_a_compressed_image:
adjusting the block size varies speed vs compresion ratio.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=164015
create_compressed_fs has been worked on recently , you may find it works faster if can install the lastest version.

Thanks for not doing the leg work yourself ;) I found some useful info along the way.

HTH

[knoppu]

If all else fails , read the manual ;)


http://www.knoppix.net/wiki/Knoppix_Remastering_Howto#Test_remastered_version_ without_creating_cloop_file.2Fiso