Sugar on a Stick/Stick Layout - Revision history

FGrose at 02:31, 27 September 2010

2010-09-27T02:31:55Z

← Older revision		Revision as of 22:31, 26 September 2010
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	It has been shown that if you take a stick that is stuck at login and you copy over a fedora-overlay file from a working stick, the stick will boot again. Thus we are confident that the problem is corruption of the overlay file.		It has been shown that if you take a stick that is stuck at login and you copy over a fedora-overlay file from a working stick, the stick will boot again. Thus we are confident that the problem is corruption of the overlay file.
			: It may also be exhaustion of the overlay. See [[LiveOS image]]. --[[User:FGrose\|FGrose]] 22:31, 26 September 2010 (EDT)

	''Next Steps'' - Try some alternate file structures.		''Next Steps'' - Try some alternate file structures.

Grantbow: bug typo

2010-09-27T01:43:58Z

bug typo

← Older revision		Revision as of 21:43, 26 September 2010
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	====There is a bug around restarting====		====There is a bug around restarting====
	It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket {{bug\|1069]]		It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket {{bug\|1069}}

Satellit: /* Sticks are being improperly removed */

2010-03-12T12:28:11Z

Sticks are being improperly removed

← Older revision		Revision as of 08:28, 12 March 2010
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	Yes they are, but its not at all clear to me that that correlates with the sticks that are failing.		Yes they are, but its not at all clear to me that that correlates with the sticks that are failing.

			'''Current experements on delayed writes from cache in live usb's '''[http://wiki.sugarlabs.org/index.php?title=Talk:Sugar_on_a_Stick/Stick_Layout&action=edit&redlink=1]

	====There is a bug around restarting====		====There is a bug around restarting====
	It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket {{bug\|1069]]		It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket {{bug\|1069]]

Satellit: /* Sticks are damaged during formatting or burning */

2010-03-10T16:24:38Z

Sticks are damaged during formatting or burning

← Older revision		Revision as of 12:24, 10 March 2010
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	If we understood how to win and we had our own stick creation activity perhaps we would have less failures.		If we understood how to win and we had our own stick creation activity perhaps we would have less failures.
	*Look at [http://wiki.sugarlabs.org/go/Category_talk:Live_USB] for a working method to do this.		*Look at How To Sugarize liveusb-creator:[http://wiki.sugarlabs.org/go/Category_talk:Live_USB] for a working method to do this.

	====Sticks are of poor quality====		====Sticks are of poor quality====

Satellit: /* We need a more robust files system */ add link

2010-03-10T15:46:34Z

We need a more robust files system: add link

← Older revision		Revision as of 11:46, 10 March 2010
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	# Create a Fedora Full Install USB Stick, restart it a bunch of times and see if it does better. How much space will the Fedora Full Install take?<br>So far its > 4GB http://wiki.sugarlabs.org/go/VMware#Full_Install_with_F11_Net_install_CD_to_USB_Stick		# Create a Fedora Full Install USB Stick, restart it a bunch of times and see if it does better. How much space will the Fedora Full Install take?<br>So far its > 4GB http://wiki.sugarlabs.org/go/VMware#Full_Install_with_F11_Net_install_CD_to_USB_Stick
	# Create an Open Suse USB Stick, restart it multiple times and see if it fails. How much space does it use?		# Create an Open Suse USB Stick, restart it multiple times and see if it fails. How much space does it use?[http://wiki.sugarlabs.org/go/Sugar_on_a_Stick/Linux/openSUSE] Note the second partition for persistence
	# Create Alternate ex3 File Structured, non-live, blueberry USB [http://people.sugarlabs.org/bernie/soas-2-blueberry-direct-2GB.img.xz] (The resulting partition size on the USB can be resized with gparted if more storage is needed)[http://people.sugarlabs.org/Tgillard/soas-2-blueberry-direct-cleared-3GB.txt]		# Create Alternate ex3 File Structured, non-live, blueberry USB [http://people.sugarlabs.org/bernie/soas-2-blueberry-direct-2GB.img.xz] (The resulting partition size on the USB can be resized with gparted if more storage is needed)[http://people.sugarlabs.org/Tgillard/soas-2-blueberry-direct-cleared-3GB.txt]

Satellit: /* Sticks are damaged during formatting or burning */ How To Sugarize liveusb-creator

2010-03-10T15:39:55Z

Sticks are damaged during formatting or burning: How To Sugarize liveusb-creator

← Older revision		Revision as of 11:39, 10 March 2010
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	There was a detailed discussion thread back in February at: http://lists.laptop.org/pipermail/devel/2009-February/022987.html		There was a detailed discussion thread back in February at: http://lists.laptop.org/pipermail/devel/2009-February/022987.html

	If we understood how to win and we had our own stick creation activity perhaps we would have less failures.		If we understood how to win and we had our own stick creation activity perhaps we would have less failures.
			*Look at [http://wiki.sugarlabs.org/go/Category_talk:Live_USB] for a working method to do this.

	====Sticks are of poor quality====		====Sticks are of poor quality====

Satellit: /* We need a more robust files system */ ext4 and data loss and ex3 File Structured, non-live, blueberry USB

2010-03-10T15:36:06Z

We need a more robust files system: ext4 and data loss and ex3 File Structured, non-live, blueberry USB

← Older revision		Revision as of 11:36, 10 March 2010
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	# Create a Fedora Full Install USB Stick, restart it a bunch of times and see if it does better. How much space will the Fedora Full Install take?<br>So far its > 4GB http://wiki.sugarlabs.org/go/VMware#Full_Install_with_F11_Net_install_CD_to_USB_Stick		# Create a Fedora Full Install USB Stick, restart it a bunch of times and see if it does better. How much space will the Fedora Full Install take?<br>So far its > 4GB http://wiki.sugarlabs.org/go/VMware#Full_Install_with_F11_Net_install_CD_to_USB_Stick
	# Create an Open Suse USB Stick, restart it multiple times and see if it fails. How much space does it use?		# Create an Open Suse USB Stick, restart it multiple times and see if it fails. How much space does it use?
			# Create Alternate ex3 File Structured, non-live, blueberry USB [http://people.sugarlabs.org/bernie/soas-2-blueberry-direct-2GB.img.xz] (The resulting partition size on the USB can be resized with gparted if more storage is needed)[http://people.sugarlabs.org/Tgillard/soas-2-blueberry-direct-cleared-3GB.txt]


	''Background Links''		''Background Links''
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	''Theories that have evidence against them''		''Theories that have evidence against them''

			*ext4 and data loss:http://lwn.net/Articles/322823/ (It looks like ext3 formatting may be more robust in a USB)

	Dave Bauer was able to replicate the failure easily by restarting a Sugar stick. This means its probably not:		Dave Bauer was able to replicate the failure easily by restarting a Sugar stick. This means its probably not:

Sascha silbe: use bug template for bug links

2010-03-10T13:36:09Z

use bug template for bug links

← Older revision		Revision as of 09:36, 10 March 2010
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	Here is an idea for an alternative USB Format: [[http://wiki.sugarlabs.org/go/Sugar_on_a_Stick/USB_format]]		Here is an idea for an alternative USB Format: [[http://wiki.sugarlabs.org/go/Sugar_on_a_Stick/USB_format]]

	Also see Ticket 907 ~~[[http://dev.sugarlabs.org/ticket/907]]~~		Also see Ticket {{Bug\|907}}

	A 2 GB USB is about $.60 more then a 1GB stick. If we need to compress less to get robustness its ok for us to require a 2GB USB. A 4GB stick is about $2.50 more then a $1GB Stick.		A 2 GB USB is about $.60 more then a 1GB stick. If we need to compress less to get robustness its ok for us to require a 2GB USB. A 4GB stick is about $2.50 more then a $1GB Stick.
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	====There is a bug around restarting====		====There is a bug around restarting====
	It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket ~~1069 [[http://dev.sugarlabs.org/ticket/~~1069]]		It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket {{bug\|1069]]

FGrose: moved Stick Layout to Sugar on a Stick/Stick Layout: restructure for greater discoverability

2009-11-01T22:32:26Z

moved Stick Layout to Sugar on a Stick/Stick Layout: restructure for greater discoverability

← Older revision	Revision as of 18:32, 1 November 2009
(No difference)

CarolineM: Created page with '''Failure Modes'' # Gets stuck at Fedora Login ## With liveuser prefilled
I was able to repeatably create this failure when I was testing a version of schoolserver.py that h…'

2009-08-04T00:55:56Z

Created page with '''Failure Modes'' # Gets stuck at Fedora Login ## With liveuser prefilled I was able to repeatably create this failure when I was testing a version of schoolserver.py that h…'

New page

''Failure Modes''

# Gets stuck at Fedora Login
## With liveuser prefilled I was able to repeatably create this failure when I was testing a version of schoolserver.py that had a typo in it.
## With nothing prefilled This error has successfully been replicated by Restarting multiple times.
# Bug in initramfs /init detected. Dropping to a shell. Good luck! bash: no job control in this shell. Stick abuse, like putting it through the washing machine, seems to precipitate this type of failure.
# Freezes during use of an activity. Rebooting on the same computer doesn't help it still freezes on the same activity. One time we rebooted on a different computer and it worked.

We don't know the root causes but we have plenty of theories.

Sticks will always fail. There will always be multiple causes for failure. This problem has to be addressed like a process engineering issue. Is stick failure a major cost in time or money? Find the largest cause of failure. Fix that to improve yield. Is stick failure a major cost in time or money? Find the the remaining largest cause of failure.....

This summer we had probably 10 sticks fail for 35 students. That is a major cost in time and money. The most common unrecoverable failure mode was stuck at Login.

====We need a more robust files system====

It has been shown that if you take a stick that is stuck at login and you copy over a fedora-overlay file from a working stick, the stick will boot again. Thus we are confident that the problem is corruption of the overlay file.

''Next Steps'' - Try some alternate file structures.

# Create a Fedora Full Install USB Stick, restart it a bunch of times and see if it does better. How much space will the Fedora Full Install take? So far its > 4GB http://wiki.sugarlabs.org/go/VMware#Full_Install_with_F11_Net_install_CD_to_USB_Stick
# Create an Open Suse USB Stick, restart it multiple times and see if it fails. How much space does it use?

''Background Links''
Thread from the Fedora Forum: [[http://forums.fedoraforum.org/showthread.php?t=221719]]

Here is an idea for an alternative USB Format: [[http://wiki.sugarlabs.org/go/Sugar_on_a_Stick/USB_format]]

Also see Ticket 907 [[http://dev.sugarlabs.org/ticket/907]]

A 2 GB USB is about $.60 more then a 1GB stick. If we need to compress less to get robustness its ok for us to require a 2GB USB. A 4GB stick is about $2.50 more then a $1GB Stick.

''Theories that have evidence against them''

Dave Bauer was able to replicate the failure easily by restarting a Sugar stick. This means its probably not:

* The Bulk Copier, Dave doesn't have one.
* The older slower computers and USB 1 ports we are using at the GPA.

====Sticks are damaged during formatting or burning====

http://wiki.laptop.org/go/How_to_Damage_a_FLASH_Storage_Device [[http://wiki.laptop.org/go/How_to_Damage_a_FLASH_Storage_Device]]

There was a detailed discussion thread back in February at: http://lists.laptop.org/pipermail/devel/2009-February/022987.html

If we understood how to win and we had our own stick creation activity perhaps we would have less failures.

====Sticks are of poor quality====

Here is an explanation of two processes used to create USB sticks: http://www.solutiongrove.com/blogger/2008/09/08/there-are-two-type-of-usb-flash-memory-slc-and-mlc [[http://www.solutiongrove.com/blogger/2008/09/08/there-are-two-type-of-usb-flash-memory-slc-and-mlc]]

====Sticks are being improperly removed====

Yes they are, but its not at all clear to me that that correlates with the sticks that are failing.

====There is a bug around restarting====
It is very common to fail after a restart, the system forgets its supposed to go to Sugar. See ticket 1069 [[http://dev.sugarlabs.org/ticket/1069]]