Douglas McClendon <dmc.fedora(a)filteredperception.or wrote:
>If that doesn't help or answer you question, try to add more detail to
Thanks for the reply.
I use the live usb tools to create my live USB stick with a 2047 MB
overlay. I boot from it and let it run updates. I reboot the LiveUSB to
make sure it still boots, then I shut down. I boot a system on a copy
of Fedora 9 on the hard drive and plug in my Live USB so I can see the
files on my USB stick.
I see 2 folders:
in the LiveOS folder I see three files:
squashfs.img looks to be the size of the live iso
overlay-FEDORA-3099-53F2 looks to be the size of the overlay and has
overlay in the file name
osmin.img is only 8k probably a boot strap, I'm not sure.
osmin.img is part of an optimization used during the install-to-disk
process. Interesting long story, but should not be relevant here.
I'm sorry, I can't find anything on the LiveUSB file structure on the
WiKi. I've signed on as a writer for the Fedore project so I'd like to
write it once I figure out what it is.
Sounds like a good plan. I don't have the free time I used to when I
was happily unemployed, but I'll try to help.
I was hoping that I could backup the overlay file and the syslinux
folder from my completely updated LiveUSB stick and restore them to a
newly built LiveUSB from my backup.
I think this should work, but there may be some subtle wording here.
What you said almost sounds like boiling down to doing a straight
duplication of a LiveUSB, which AFAIK should work. To the extent that
it doesn't work, we should focus on how what you are doing is different
than a pure duplication.
> I'm not entirely sure what you mean. One thing that is possible is to
> copy the overlay file from one liveusb and put it on another. Though
> the format of the overlay file is inherently tied to the specific liveos
> it was originally with. I.e. you won't be able to copy an overlay file
> from an f9-x86 liveusb onto an f9-x64 or f10-x86 liveusb. Or even a
> customized f9-x86 liveusb that you created with livecd-creator/tools.
Nothing fancy - The same USB stick, built in the same way with the same
iso and the same overlay size.
The overlay file name changes. I've given the updated file (the overlay
that was part of the LiveUSB for all of the updates) the same name as
the new file that is created and left the updated file with its original
name. I've overwritten just the overlay itself and the overlay and every
combinarion of the osmin.img and squashfs.img files.
This sounds reasonable. Now, if this is a new LiveUSB built from the
same LiveCD, the osmin.img and squashfs.img should be 100% identical.
Same file sizes, same md5sums. If they aren't, mention that.
I could never get it to boot. The boot starts but then hangs.
What is the last thing you see when it hangs?
Ideally, it would be great to specify the overlay and the syslinyx
folder that goes with that overlay in the command line to build the
Unfortunately the syslinux folder is hard coded and is a limitation of
syslinux (actually you get 2 or 3 choices, but not an arbitrary choice).
The overlay file name is part of our code, and is keyed off of the
UUID of the usb disk (in this case). I can't say off the top of my head
(it's been awhile) whether making the filename specifiable on the
commandline is trivial or not.
At this point I would be thrilled if I could get a set of manual steps
together to have an updated system without going through the update
process. I loose a day each time.
If I find the time, I'll try to reproduce your problem. An absolute
brute-force method that should work for identical sized usbsticks would
be a bit for bit copy. I.e. if you set up one 4G LiveUSB and it works,
you should be able to plug it in, and if it is seen as perhaps /dev/sdX
and then you plug in another 4G usbstick seen as /dev/sdY, you should be
able to run
dd if=/dev/sdX of=/dev/sdY
and get a working clone. (note, you may have the partition visible as
/dev/sdX1, but use the whole device as above for the duplication).
> From an engineering standpoint, of course anything is possible. One
> use case I see, is to use the persistence feature to add an entry to
> fstab, such that say, /mnt/data mounts to a ext3fs image located on a
> file on your liveusb. You can then add a user that has a home directory
> under there, and perhaps install applications under there. In this way,
> you could then copy that ext3fs image file to an f10 liveusb, and then
> only have to re-do the fstab and passwd modifications, such that
> everything now pretty much looks the same.
Your suggestion of building a file structure that would transcend
different releases would be awesome but alas I need to crawl before I
Any help would be greatly appreciated.
Hope the above helps. And as mentioned, if I find the time, I'll try to
reproduce your less brute-force method of copying, which sounds pretty
reasonable, but clearly isn't working for some reason or another.
And just post any wiki/work-in-progress and I'll be happy to provide