Talk:UBIFS on XO

From OLPC
Jump to navigation Jump to search

Hi,

I would like to comment this:

"AXFS is not upstream and may not meet our needs. BtrFS is close to being integrated into kernel.org but as experimental, in-development code. YAFFS2 is deployed in quantity but the maintainer has not expressed interest in pushing it upstream and it does not support compression."

1. AXFS is read-only file-system so it is for sure not appropriate. 2. BtrFS is designed for block devices. Yes, I know it is special and log-structured,

  but it is not realistic to use it on Flash, I believe. These talks are just
  speculations in my opinion.


Also let me comment this: "UBIFS, like JFFS2, supports LZO and ZLIB compression. Unlike JFFS2, it can be enabled and disabled on a per-inode basis via a "chattr -c" shell command or a call to the FS_IOC_GETFLAGS ioctl."

Our experience is that user-space people are reluctant to use this feature. They want the FS to be smart and automatically do this. Well, it is possible to implement and should really not be too difficult.

Also, you guys probably should know that UBIFS does not support NFS so far, but we'll implement it, especially if you say you this.

Vs testing - it is of course the required and appreciated thing. Just wanted to comment "How does it act on power failure?". We extensively tested this on our devices. We've done over 10000 unclean reboots while running fsstress test from LTP. It worked fine. I mean, we paid special attention to this aspect, may be more attention than to other aspects.