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

Fri Jun 11 08:35:11 UTC 2010

This is all getting rather acrimonious and unbecoming.

I am firmly of the opinion that 10% is a very significant saving. I
often put custom live cd images together, and I have had many a time
where I've come up against the limits of the device (CD, DVD or USB
stick). Being able to get 10% more content would have made a big
difference. The circumstances have varied considerably, but it's never
been games-related--it's a much more general issue.

The two counter-arguments seem to be:

    (1) that syslinux was rejected, which is small;

    (2) that it might introduce unnecessary bugs.

I haven't followed the thread of (1), but it's a separate issue as to
whether syslinux is worth the extra space, even if it's small. In any
case, custom builds are always free to include or not include syslinux.
If you don't like what's on the base DVD, build your own--that's the
whole point of this list.

I don't accept (2). Obviously any change needs thorough testing, but
there are procedures for that, that's what rawhide is for, and we even
have a list (this one) where people can get additional help. Like
anything else, it won't see the light of day (stable repos) if it
doesn't work properly.

James

On Fri, 2010-06-11 at 08:28 +0100, Jasper Hartline wrote:

> >> Ok. So -in your opinion- 400MB is not insignificant.
> >> Go ahead and enlighten me on what is an insignificant value of space
> >> in your opinion.
> >
> > For the games spin, probably about 1 MB. Even 10 MB can be useful, but
> > there is some variability due to changes in packages, so you can't cut
> > the image size to close to the 4 GiB limit (by Spins SIG policy that's
> > the limit, not 4.7 GB) or the spin might break just before the release.
> 
> Yes 924K which is the size of syslinux package, is less than a single
> MB, which you stated on my thread
> would be too much in your opinion to put on the base DVD ISO for
> Fedora, but here where it is something that matters
> to you, it is an insignificant amount of space. Very interesting.
> Please explain your logic on the issue regarding mksquashfs w/ lzma
> being a significant savings..
> your opinion of insignificant being 1MB or 10MB, and the fact that you
> said in the already 3.2GB large DVD ISO
> that adding syslinux which is in the range of insignificant size in
> your opinion would take up too much space
> where 3.2GB is 800 MB less than as large as it will get within
> specification, which is twice as large as the
> _really significant amount_ of space you will save using mksquashfs w/
> lzma at 400MB.
> 
> I really want to read your response on this one.
> 
> 
> 
> >> > The games spin is just under 4 GB. A 10% savings there is approximately
> >> > 400 MB.
> 
> You must really really like games, because 4GB of compressed games
> uncompressed to about 7GB or more.
> 8 GB probably which would have me playing games so long I wouldn't
> even have time to play
> the extra games which you include in 400MB with your squashfs w/ lzma,
> another useless feature
> games no one would have time to play, excellent.
> 
> 
> > The games spin is a DVD image. The same code is used, it just targets a
> > different media size. (Actually the limit is 4 GiB so that windows users
> > can download the images in most cases.)
> 
> I am not focused on development of livecd-creator nor any part of
> livecd-tools which taregt Windows
> users, livecd-creator does not run on Windows, or at least I don't
> think it does.
> In any event, I am not concerned with this reasoning.
> 
> 
> 
> 
> > The next merge window will be in August. The patches might even show up
> > before then. It just depends on whether or not Phillip gets to work on them.
> > I don't need to wait for those patches to land to test the 4.1 version
> > of squashfs-tools to make sure it works with zlib and to see if there
> > are obvious performance issues with mksquashfs. I can also test changes
> > to livecd-creator to make sure that the changes to allow for specifying
> > lmza compression don't break things for zlib compression.
> 
> Sounds like a patch set that will exist on your machine, as I stated a
> simple corner case.
> Submitting these patches to the list or committing them will do you no
> good if you expect feedback.
> 
> You would be the only person with that patch set and specific
> configuration in a whole fiasco of pretzel
> code so you can put 400MB of games on a games spin. Seems unreasonably useless.
> 
> 
> > get some idea if the live image performance is going to have problems I
> > can build a kernel with the developmental patches the Phillip has sitting
> > in his git repo now. The latter won't be real high priority, as they
> > may perform a lot differently than the final version.
> 
> What gives you the idea that your testing locally at your location
> will produce a significant difference
> than the performance on a final ISO, are you using a Pentium 486 with
> a recompiled Fedora kernel to support
> that chip? If not I see no reason why you would expect or even want to
> test this aspect of the
> mksquashfs w/ lzma.
> 
> These games spins don't need to run on a Cisco router, and a Intel i7
> 8 core machine.
> 
> >> Also nobody can test something simple like squashfs w/ lzma
> >> compression and a kernel with this support without
> >> having a local, Everything synced repository mirror or access to a
> >> network with one.. due to syslinux not being available on the DVD ISO
> >> nor livecd-creator honoring repo directives with teh --cost specified.
> >
> > This makes no sense. Live DVD images work.
> > If you want to use specific repos, you can specify them in your kickstart
> > files.
> 
> Again, you are purposely ignoring the comment, I cannot use just a DVD
> ISO of Fedora 13
> to do simple _testing, even if I wanted to because I do not enjoy
> needing to have to download
> ridiculous amounts of data over the network when simply putting the
> syslinux package on teh base DVD ISO
> for Fedora alleviates this problem.
> LiveDVD images DO NOT WORK, using livecd-creator and a DVD ISO as a
> configured repository
> due to the requirement on syslinux package.
> 
> 
> >But certainly if you are going to be doing a lot of DVD sized
> > composes it makes sense to have a local copy of the repos you want to use.
> Now you're being obtuse, and that is all.
> To test the mksquashfs w/ lzma I don't need to create DVD sized images.
> Once real technical and important bugs are fixed is when I would move
> on to creating large DVD
> images which are spins with livecd-creator. To test a kernel and
> squashfs-tools I don't need to install more than maybe 200 packages
> which do not come close to nearly even not fitting on a  CD, let alone
> a DVD.
> 
> 
> 
> > So what are you doing about getting it to happen? You can't really think
> > that trying to persuade me to not work on lzma compression for live images
> > is going to get me to work on adding syslinux (in addition to or instead
> > of isolinux) to live images.
> 
> You have no real reason to care what I am doing about the syslinux
> situation, you have already
> stated it isn't important to you and I sincerely believe you.
> You state that it would provide no significant advantage since the DVD
> ISO installer image
> is already up to it's gills at 3.2GB and adding a 1MB package to
> alleviate all the issues I present regarding this,
> is not worth the space which needs to be conserved in your opinion,
> which will make the DVD too large by specifications not even set in
> stone, nor created by you.
> 
> 
> > I already have enough Fedora stuff I can work
> > on to keep me busy full time, if I had that much time to do it.
> 
> I still think you're wasting your time. Nobody cares about mksquashfs
> w/ lzma unless
> it provides some significant advantage, and 400MB on a games spin is
> not a high priority to anyone except
> yourself.
> 
> Perhaps this is just some idea you had in mind to work on, but good luck.
> --
> livecd mailing list
> livecd at lists.fedoraproject.org
> https://admin.fedoraproject.org/mailman/listinfo/livecd

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