[Sugar-devel] Hello, was Re: Hack to get a USB/SD to autologin to only "Sugar-desktop on a stick". from a F12-alpha live CD

[David Farning]

Thanks for joining us Douglas.

I would like to point out that there are two separate yet interlinked
issues at hand:
1. Easy and fast install.
2. Running OS natively on removable solid state media.

Douglas' Liveos solved the first issue.  It is very fast and easy to
install an OS to a hard drive by dd'ing the contents of the overlay to
the hard drive.

I am suggesting that ease of installation to another medium is not
longer the primary usecase for SoaS.

The primary use case is now running Sugar and the underlying OS as
natively as possible on the removable solid state media.  The primary
goals are now reliability and speed.

The issue is not that overlays are bad/good or real file systems.  The
issue is, can SoaS improve stick reliable  and speed by eliminating
the overlays and writing the _contents_ of the overlay directly onto
the solid state device using a file systems which is aware of the
design characteristics of current generations of USB keys.

I have been conducting some very initial tests using WAD's SD card test tools.
#1. Standard SOAS.
#2. Install the contents of the SoaS overlay to a usb key using ext2.

I am just running various methods of installing soas on USB sticks in
qemu directly from usb sticks using

qemu  -hda /dev/sd*

My initial runs using the cheapest drives I could find at best buy
indicate that #2 has at least 10X the lifetime as #1.

david


On Wed, Sep 9, 2009 at 10:27 AM, Martin Dengler<martin at martindengler.com> wrote:
> On Wed, Sep 09, 2009 at 06:48:53AM -0600, Douglas McClendon wrote:
>> Douglas McClendon wrote:
>> > Martin Langhoff wrote:
>> >> On Wed, Sep 9, 2009 at 4:26 AM, Douglas
>> >> McClendon<dmc.sugar at filteredperception.org> wrote:
>> >>> My name is Douglas McClendon, and I created the ZyX-LiveInstaller which appears
>> >>>  on track to becoming part of SoaS.  I also can accept praise and blame for
>> >>> the LiveUSB persistence feature I implemented for fedora a couple years back,
>> >> Good to have you on board! One thing we've found is that the overlay
>> >> fs trick is neat but somewhat fragile. In brief - unclean shutdowns
>> >> and "oops, I pulled out the stick" cases very often leave the USB
>> >> stick unbootable.
>> >>
>> >> Of course, first step is fsck.vfat, but after that, we're completely
>> >> lost. Hints would be more than welcome. Ideally, something smarter can
>> >> be done during the boot itself or otherwise with a "repair" script.
>> >
>> > Unfortunately I don't have any easy answers.  As someone who works on NDS
>>
>> Ok, more hints as various vague theories start percolating through
>> my memory.
>
> If people care to take advantage of your expertise, I hope they can
> provide the filesystems that have failed as examples.  "overlay is
> fragile" is about the level of FUD, AFAICS.  Nothing better has been
> proposed.  No broken filesystems have been made available.  I don't
> doubt the "some sticks 'broke' when yanked out before fs's were
> sync'ed" reports in and of themselves, but when this meme continues it
> makes potential contributors / onlookers think there is some obvious /
> neglected problem.
>
>> -dmc
>
> Martin
>
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