At Wed, 17 Aug 2011 13:11:51 +0200, Arnd Bergmann wrote:
On Wednesday 17 August 2011, James Tunnicliffe wrote:
One thing I noticed during Ubuntu boot on my Panda was that the mount process would say that it detected btrfs was running on a flash card and it had enabled flash mode. I don't know what is different in flash mode and I don't know if when I let Ubuntu auto-mount a flash card for testing on my Laptop if it enabled it. The only mount option I can find that sounds right is "ssd", which isn't on when I just tested it now.
Good point. Tixy, do you know what mode you were testing btrfs with?
btrfs understands the 'ssd', 'ssd_spread' and 'nossd' mount options that should have a significant impact here, although it's not clear which of these is best for a flash memory card, since the characteristics of SD cards are very different from SSD.
The version of btrfs that I'm looking at does not have any optimization for cheap flash drives, only for SSD.
does anyone checked on seekwatcher[1], a visualizing tool Chris Mason has wrote. I'm pretty sure that Chris would like to hear what went good and bad for btrfs as an embedded system's root file system.
[1]:http://oss.oracle.com/~mason/seekwatcher/
just my 2 cents.