uSD corruption (OT?)

[Boudewijn]

On Saturday 17 December 2011 23:10:02 Doug Jones wrote:
> On 12/16/2011 01:08 AM, Radek Polak wrote:
> > On Thursday 15 December 2011 22:00:22 fdvjoif at vodafone.it wrote:
> >> Hi
> >> I have a Kingstone microSD card 8GB. It seems to be reliable for data
> >> but if I use it with a running distro, at this moment QtMoko, I
> >> experience, during a day of usage, several freezings. I mean, when it is
> >> in suspend mode (deep suspend enabled) if I press the power button the
> >> Neo does not recover from the suspend. I have to pull off the battery
> >> and then restart the Neo, but as can you imagine, after a couple of
> >> times the file system gets corrupted and I have to format the partition.
> >> Moreover this behaviour seems to become worse as the time passes.
> >> Should I consider to replace the uSD card? are there known issues in
> >> using running distro on it?
> >> Thanks.
> > 
> > For me uSD card never worked as stable rootfs. I always ended up with
> > corrupted filesystem after a couple of days. But for data on FAT it
> > always worked quite good.
> > 
> > I guess this is some flaw in Freerunner's hardware or kernel driver. On
> > GTA04 i have rootfs on uSD and no problems at all. I am starting to
> > think that NAND on GTA04 is quite useless - it would be quite cool if it
> > had 2 uSD cards instead (with BTRFS as fs it could rock).
> 
> There have been endless discussions over the years, about file systems,
> race conditions, suspend modes, the gravitational influence of
> Jupiter...  But I have never heard anyone claim that they actually
> understand why a card that Just Works in my camera can't be made to Just
> Work in all of our open source devices.
> 
> 
> Yes, I know this isn't very constructive...  Sometimes I just have to
> vent...   :-)

You are probably familiar with/aware of linux-mtd at infradead.org. Part of 
their FAQ made me suspect optimizations for FAT or parts of the spec left out 
of the flash translation layer giving problems with anything but FAT [1]: 
"(...) we suspect that vendors may user various tricks or compromises to keep 
their devices "good enough" and cheap. For example, it is known that some 
vendors optimize their FTL devices for FAT, and if you start using ext3 on top 
of one, you might face some unexpected problems (...)"

Not very constructive either :-( But a good read if you didn't after all ;-)

Boudewijn 

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