Re: Samsung RFS Filesystem

[Ludovic Guilhamat <lguilhamat@perax.fr>]

Charles Manning a écrit :

>On Tuesday 31 May 2005 23:42, Ludovic Guilhamat wrote:
>  
>
>>Hi,
>>
>>I would maybe interested in testing the Samsung RFS File System...
>>
>>Does someone, here, already used it, and what are the conclusions ?
>>    
>>
>
>
>Please do do some testing. It would be good to see the results, positive or 
>negative.
>
>I have not used it, but from a description I can draw some immediate 
>conclusions.
>
>RFS = Robust FAT file system
>
>>From the blurb at 
>http://www.samsung.com/Products/Semiconductor/Flash/TechnicalInfo/rfs.htm
>
>this looks a bit like FATFS running on top of DOC. It might have some 
>transactioning which would make it look a bit more like Microsoft's TFAT.
>
>Neither of these are a proven reliable system. DOC can still get FAT 
>corruptions if you don't umount before power loss (== potentially a 
>completely scrambled fs). TFAT is completely unprovedn and is slower and not 
>always robust (not robust with typical mount options). Perhaps RFS gets the 
>robustness right.
>
>
>Running FAT on NAND costs some performance due to the FTL etc.  To make a 
>journaling system on FAT, as RFS claims, costs even more performance.
>
>IMHO: If you want robustnes on NAND use a log structured fs designed for 
>flash: YAFFS or JFFS2.
>
>For completeness, I will state that I wrote YAFFS, but I don't think this 
>biases my answer.
>
>-- CHarles
>
>  
>
Thanks.

Actually, the system I work on uses Jffs2 (Coldfire with uClinux). But, 
mount times are very long (the memory is a Flash Nand 16Mb). So, I 
planned to test Jffs2 patches (from the Jffs2 Improvement Project), then 
Yaffs. And as RFS is not freely distributed, and I don't know yet its 
cost, I wanted to know if someone had tested it.

Thanks for your response.

Ludovic.