Talk:Debian Jessie on XO

last?

In the History page,

2015-11-26T07:01:56 Quozl (Talk | contribs) (6,793 bytes) (using last instead of ext, ...

last is a synonym for ZFS? Another file system? A typo? Thanks, ... Peasthope 05:31, 23 December 2016 (UTC)

Nothing to do with filesystem type; firmware detects that automatically. No, not a typo. Did you look at the difference between revisions to understand the edit? ext and last are device name alias in the firmware, see bootparam.fth for how last is defined. --Quozl 18:33, 23 December 2016 (UTC)

Thanks. I was tired and thinking file systems rather than Forth.

Ext4 on an SD Card

Instructions include "An SD card ... formatted to ext4 ...". According to most discussions, best current practice with flash storage is ext4 without journaling. Options for file system creation and mounting here.
http://fenidik.blogspot.ca/2010/03/ext4-disable-journal.html
Any additional tips? Thanks ....Peasthope 18:04, 16 January 2017 (UTC)

Disabling the journal will damage your filesystem when the XO-1 runs out of battery power and is not plugged in. Batteries made in 2007 or 2008 should be very ready to fail. If you need I/O performance, you should not be using an XO-1. The XO-1 design is from 2006. A Raspberry Pi 3 outperforms an XO-1 by an order of magnitude or two. Our kernel is after that blog post by three years, (2013 vs 2010), so I don't think the post is of use except to suggest things to test if a system is I/O bandwidth constrained. You must have a performance measurement method, and use it before and after the change, to see what the effect is. So what is your measurement method? The best way to reduce I/O delay on the XO-1 is to remove I/O demand; size the application demand to fit the available memory (256 MB), so that enough of the filesystem metadata is in cache. Exceed the available memory and the system will begin to discard and then re-read metadata. To reduce the application demand, avoid running programs that are not needed, and do not run a web browser. Hardly practical with today's focus on web sites, but I've no idea what your overall use for your XO-1 is. --Quozl 21:46, 16 January 2017 (UTC)

"Disabling the journal will damage your filesystem ..."

Whereas journaling is claimed to shorten the life of the SD card. Computers were used successfully with ext2 and fsck. Is journaling necessary?

"... when the XO-1 runs out of battery power and is not plugged in."

With a properly working power system, the low battery warning allows clean shutdown. Correct?

"XO-1"

1.5 here.

Debian interests me for these reasons.

• I use Debian on other machines. Debian on the XO is one less system to contend with.
• For package management, I prefer aptitude over yum.
• In my experience, configuration of TLS is automated better in Debian than in stock OLPC. I might have missed a helpful package.
  

"So what is your measurement method?"

Performance is a secondary concern. If Debian is noticeably slower than OLPC on the 1.5, I'll have to consider the trade-offs.

"A Raspberry Pi 3 outperforms an XO-1 by an order of magnitude or two."

Worth noting. A http:://wiki.laptop.org/Performance_comparisons page cou‎ld be worthwhile. I'm not aware of any other machine with housing, reliability, ruggedness, screen legibility and water resistance competing with the XO.

"I've no idea what your overall use for your XO-1 is."

Desktop systems work well at home or office. The XO is well suited for travel. A little text editing and Web access. Nothing sophisticated. The XO is also helpful for reading documentation when a desktop machine is out of commission.

Regards, ... Peasthope 18:43, 17 January 2017 (UTC)