Why do you use file system at all? Some time ago I had a lot of problems with
unreliable usb storage writes. After trying different fs solutions, I finally
solved the problem with a simple dd. Set of files that I want to store I pack
to tbz2 and write it down to one of several known locations on storage device,
using dd.
After restart, I go through those locations searching for a good copy of data...
OK, my real solutions is somewhat more complicated than this, because I need
*latest* valid set of files, but in your case it seems to be overkill.
Wear leveling is done by usb/sd card cpu, and that's it. No file system, no
fsck, no delays. The only delay end user can experience is when first copy is
damaged, so you have to go on to second or third...
--- In "Blair" <> wrote:
>
> Okay, after a chat with Kris at TS, I know that the sync command will cause
> the file system buffers to be written to the SD card. Okay, fine but I still
> find that if you don't unmount the read/write JFS partition, you have to fsck
> the /dev entry before the system will let you mount it after a restart. That
> defeats the purpose, IMHO. Seems to me that any use of fsck is evil because
> you don't know how long it will take to complete and if you have a faceless
> embedded system, the layperson will think it's broken.
>
> So my next experiment is to try an EXT3 partition. That has one benefit in
> that it can be much smaller than the minimum JFS partition which is 16MB. Of
> course I had to rebuild the kernel with EXT3 support. I seem to be able to
> skip the sync operation (unless that was a bug in earlier JFS implementations
> as I went from 2.6.21 to 2.6.34). I do see mount warnings telling me to run
> fsck.
>
> So, does anyone have more real-world experience here? Technically, I'm only
> writing to a very small preferences/settings file and never leave the file
> open for more than it takes to write out a few dozen words and then the file
> is immediately closed. The chance that the file is open when power is turned
> off is really small.
>
>
>
> --- In "Blair" <bburtan65@> wrote:
> >
> > Given a 7350 booting to the Busybox shell prompt (not full Debian).
> > The file system is mounted read-only and by design you have to run the save
> > script to write any changes to the SD card. I'd like to be able to store a
> > user-preferences file generated and modified by a C program somewhere on
> > the SD card but I don't want to have to run the save script.
> >
> > So, I tried making a new JFS partition (in place of the eclipse partition).
> > But there are two problems. First, if I make a change to something on
> > that partition (new file, edit a file, etc), and I turn off the power, the
> > system forces me to run fsck before it will let me mount the partition.
> > Second, the changes have been lost.
> >
> > What is the proper way to accomplish this? I though JFS was a power-loss
> > tolerant file system.
> >
>
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