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Re: Which file system to use?

+++ Douglas Lopes Pereira [2009-10-13 08:57 -0300]:
> Hi guys,
> According to Martin's we should format our USB stick or SD card using
> EXT2 file system. I was wondering if I can use UBIFS instead (I don't
> see any reasons not use it) but first I would like to count on yours
> expertise.

Nope. Although we call them 'flash drives' they don't present a flash
(MTD) interface - they present a block interface. 

UBIFS (and JFFS2 and YAFFS) all talk to MTD (flash) directly.
Filesystems like EXT2 talk to block devices. 

This is all very unfortunate because you are dependent for the
flash-management aspect of this on the behaviour of the secret
controller inside the stick, which is often optimised for FAT (extra
replaceable blocks at the front of the device where the cluster table
lives) and thus may wearout faster if used with other filesystems.

I believe LOGFS is intended to be a flash filesystem which can be used for
USB block device 'flash'. 

> Is there any advantage on using EXT2 instead of UBIFS?

It works. You might be able to get UBIFS on a USB stick but it won't
do any of the useful things it does because it can't see the actual

Principal hats:  iEndian - Balloonboard - Toby Churchill - Emdebian

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