https://elinux.org/index.php?title=Add_checkpointing_or_logging_to_UBIFS&feed=atom&action=historyAdd checkpointing or logging to UBIFS - Revision history2024-03-28T14:30:36ZRevision history for this page on the wikiMediaWiki 1.31.0https://elinux.org/index.php?title=Add_checkpointing_or_logging_to_UBIFS&diff=32797&oldid=prevTim Bird: Created page with "; Summary: Add checkpointing or logging to UBIFS ; Proposer: Tim Bird == Description == Currently, the UBI file system takes a long time to be ready for use, due to a badblock ..."2011-01-25T20:47:52Z<p>Created page with "; Summary: Add checkpointing or logging to UBIFS ; Proposer: Tim Bird == Description == Currently, the UBI file system takes a long time to be ready for use, due to a badblock ..."</p>
<p><b>New page</b></p><div>; Summary: Add checkpointing or logging to UBIFS<br />
<br />
; Proposer: Tim Bird<br />
<br />
== Description ==<br />
Currently, the UBI file system takes a long time to be ready for use,<br />
due to a badblock scan that takes place during initialization of UBI<br />
(the UBI attach operation).<br />
The scan takes a time that is linearly proportional to the size of<br />
flash. As flash sizes grow, the delay caused by this scan becomes a<br />
problem.<br />
<br />
It would be beneficial to eliminate the scan, or make it more scalable,<br />
using some kind of checkpointing or logging.<br />
<br />
== Related work ==<br />
* UBIFS<br />
** http://en.wikipedia.org/wiki/UBIFS<br />
** http://lwn.net/Articles/276025/<br />
* UBI2<br />
** see portions of http://www.mjmwired.net/kernel/Documentation/filesystems/ubifs.txt<br />
* Mount times<br />
** http://osl.sed.hu/wiki/ubifs/index.php/Mount_results<br />
** http://elinux.org/images/f/f8/CELFJamboree30-UBIFS_update.pdf<br />
<br />
* This proposal was suggested last year, but the project was not done<br />
** See http://elinux.org/CELF_Project_Proposal/UBIFS_mount_time_speedups<br />
<br />
=== UBI logging feature submitted by Samsung ===<br />
A developer with Samsung (in India) proposed UBIL - UBI logging - to solve this problem, in April 2010.<br />
* Initial announcement: http://lists.infradead.org/pipermail/linux-mtd/2010-February/029256.html<br />
** performance improvement: http://git.infradead.org/users/brijesh/ubil_results/blob/da4f975b5a2fc5cb2f9398bcb6b4329ba7e8c770:/nand_mount_time.pdf<br />
** patches in April, 2010: http://lists.infradead.org/pipermail/linux-mtd/2010-April/029573.html<br />
<br />
I seem to recall someone at the kernel summit (maybe Thomas) telling me that these patches<br />
improved the speed, but still had scalability proportional to the flash size.<br />
<br />
== Scope ==<br />
A rough estimate would be 3 months of development and test work, followed<br />
by some work to mainline the changes upstream.<br />
<br />
== Contractor Candidates ==<br />
* Thomas Gleixner<br />
* Artem Bityutskiy<br />
* Free Electrons<br />
<br />
== Comments ==<br />
<br />
[[Category:Project proposals 2011]]</div>Tim Bird