[Fedora-livecd-list] Progress Report: Upping the 4gb filesystem limit

[Frederick Grose]

On Sun, Jun 17, 2012 at 8:19 PM, Frederick Grose <fgrose at gmail.com> wrote:

> On Sun, Jun 17, 2012 at 6:25 PM, David Laban <alsuren at gmail.com> wrote:
>
>> Just a heads up that I'm working on a couple of patches to
>> livecd-iso-to-disk that let you up the filesystem limit.
>>
>> The current setup is:
>>
>> filesystem
>> |_ livecd.iso
>>   |_ squashfs.img --read-only?
>>      |_ ext3fs.img
>>
>> I have prototyped it, and I had to:
>>
>> * cp --sparse=always ext3fs.img <filesystem with sparse support and
>> 2.5GB free> // If I could mount the squashfs image read-write or do
>> some kind of snapshot/overlay, this would be unneccesary
>>
>> * dd seek=8GB of=ext3fs.img
>> * losetup ext3fs.img
>> * resize2fs /dev/loopX // automatically expands to fill the whole
>> 'partition' == 8GB
>> * mkdir -p tmp/LiveOS/
>> * mv ext3fs.img tmp/LiveOS/
>> * mksquashfs tmp squashfs.img // takes ages: has to re-compress 2.5GB
>>
>> Can anyone give any hints on making this more efficient, or should I
>> submit a patch to
>>
>> http://git.fedorahosted.org/git/?p=hosted/livecd;a=blob;f=tools/livecd-iso-to-disk.sh;hb=HEAD
>> as it is?
>>
>> Also, I need to do more research into snapshots (had a wild goose
>> chase grepping the kernel source for "overlay") but I think that I
>> might be able to re-compact the overlay file into the squashfs using
>> the above process. Would anyone be interested in seeing a patch of
>> that form?
>>
>
> Yes, such a patch is feasible.
> See
> http://wiki.sugarlabs.org/go/LiveOS_image
>
> for more information on the LiveOS image.
>
> I have a version of edit-livecd,
>
> http://git.fedorahosted.org/git/?p=hosted/livecd;a=blob;f=tools/edit-livecd;hb=HEAD
> , which I call editliveos.py, that uses a virtual filesystem mirror to
> merge the ext3fs.img with the overlay to create an updated, single
> filesystem image file (instead of using rsync, as the current version does
> with the --clone option).
>
> (I haven't tested the rsync version in a long time, since it failed,
> http://www.mail-archive.com/livecd@lists.fedoraproject.org/msg01052.html
> , and I haven't seen other reports of its use.)
>
> My current version of editliveos.py has a perplexing bug where an image
> built from a live running source will reboot, but one built from an
> attached LiveOS source fails to reboot.  This was not previously a problem,
> and I suspect some side effect of the systemd startup changes on the way
> new sessions or seats are authenticated.
>
> The new version involves updates to fs.py, util.py, live.py, and
> creator.py and I have not submitted patches yet for review, but I have just
> posted whole files at
>
> http://git.sugarlabs.org/soas/sugar-clone-extensions/commit/8c4e03323fc9a7e630e6c62213bb842909fbaa00
>

editliveos.py includes several new options for adjusting the image
filesystem size as well as home.img and overlay file sizes. I've posted the
output of editliveos.py --help at this wiki section,
http://wiki.sugarlabs.org/go/Sugar_on_a_Stick/Sugar_Clone#editliveos.help
(Expand the [show] frame.)

(Most of the other content on that page is from earlier work.)


>            --Fred
>
>
>> Also, I think that pre-allocating 2GB from /dev/zero on FAT
>> filesystems is pointless and needlessly slow. Doesn't the overlay grow
>> itself anyway?
>
>
> The overlay file is fixed in size.
>
> Also, isn't the limit 4GB for FAT32?
>>
>> David.
>> --
>> livecd mailing list
>> livecd at lists.fedoraproject.org
>> https://admin.fedoraproject.org/mailman/listinfo/livecd
>
>
>
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