Re: Flash filesystem

Tech Tip: Click here to run a free scan for Windows Errors and optimize PC performance

Do you have the latest QFEs installed, there are some for FAL that might
apply to your problems.

--
Bruce Eitman (eMVP)
Senior Engineer
beitman AT applieddata DOT net

Applied Data Systems
www.applieddata.net
An ISO 9001:2000 Registered Company
Microsoft WEP Gold-level Member


"turnsek" <turnsek@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:6BB490AF-CAE7-41F2-A9A3-2B12BDC1B841@xxxxxxxxxxxxxxxx
> Ok, I apologize.
>
> Our filesystem is damaged in such a way that AutoScan process could not
> repair it. I can see a lot of *.CHK files on my Storage Card and also I
can
> see files, but I can't run it. In storage manager is 2TB of unallocated
space
> visible which is most certainly not good. A release version of the image
is
> giving me a few exceptions after boot up so other drivers could not
> initialise and the image is not running. But debug version runs through
> AutoScan and boot itself up successfully except filesystem is corrupt as I
> said before.
> As I see AutoScan is trying to repair something but it's unsuccessfull.
>
> Thanks, Jernej
>
> "Bruce Eitman (eMVP)" wrote:
>
> > Jernej:
> >
> > I am concerned about your use of the work "crash". That really has no
> > meaning in an engineering discussion and should be avoided since it just
> > slows down the discussion. What is actually happening?
> >
> > Without a clearer definition it is hard to comment on it.
> >
> > --
> > Bruce Eitman (eMVP)
> > Senior Engineer
> > beitman AT applieddata DOT net
> >
> > Applied Data Systems
> > www.applieddata.net
> > An ISO 9001:2000 Registered Company
> > Microsoft WEP Gold-level Member
> >
> >
> > "turnsek" <turnsek@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> > news:C72D20BE-DCFE-45BD-AFC0-ABC68F245755@xxxxxxxxxxxxxxxx
> > > Hi!
> > >
> > > We come to conclusion that we should try other filesystems and
drivers.
> > Can
> > > you please advise us which will be good for our conditions.
> > >
> > > PS: We tried to power down (suspend) platform at least 5 seconds
before
> > > reset hits and during stress tests. The filesystem also crashes after
a
> > > number of this cycles. We are using standard Stratad driver (in public
> > > directory). Can we rule out software problems and concentrate on
hardware?
> > >
> > > Thanks,
> > > Jernej Turnsek
> > >
> > > "Bruce Eitman (eMVP)" wrote:
> > >
> > > > Zhongwei:
> > > >
> > > > As we both know all to well, you left something out of the
theoretical
> > > > discussion. The TFAT is only as stable as the media that it sits
on,
> > which
> > > > can be made to be very unstable by the driver that manages it.
Don't
> > > > misunderstand me, flash is very stable, but can be corrupted if
> > interrupted
> > > > while erasing or writing to a block, BUT TFAT can manage to survive
that
> > as
> > > > Zhongwei describes.
> > > >
> > > > The problem can happen if the media driver moves bits around on the
disk
> > to
> > > > **without** going through the TFAT, or taking other precautions to
> > prevent
> > > > corruption of data. I believe that MSFlash does compact the data on
the
> > > > Flash to make room for new data, flash failures during that can be
> > fatal.
> > > > As Zhongwei points out this is all just theoretical though. I have
not
> > been
> > > > able to prove this with MSFlash, mainly due to a shortage of source
code
> > and
> > > > time. I have been able to prove this on other Flash drivers though.
I
> > have
> > > > also found that suspend/resume can make it worse. Resets can be
managed
> > > > better because the disk can be scanned when the driver is loaded and
> > > > repaired.
> > > >
> > > > --
> > > > Bruce Eitman (eMVP)
> > > > Senior Engineer
> > > > beitman AT applieddata DOT net
> > > >
> > > > Applied Data Systems
> > > > www.applieddata.net
> > > > An ISO 9001:2000 Registered Company
> > > > Microsoft WEP Gold-level Member
> > > >
> > > >
> > > > "Zhongwei Wang" <MWang@applieddata[dot]_net> wrote in message
> > > > news:OiHxm2IiFHA.2560@xxxxxxxxxxxxxxxxxxxxxxx
> > > > > Transaction safe file systems can reliably survive the hardware
reset,
> > > > > theoretically, if it does it right. That is what they are
advertised.
> > > > TFAT
> > > > > is not reliable enough right now then it only means it is not
doing
> > > > > everything correct and it needs improvement.
> > > > >
> > > > > There is advertised idea of having two state file systems, working
> > state
> > > > and
> > > > > saved state, saved state is known good state. After a working
state
> > > > > transaction is fully finished, working state is saved or converted
to
> > > > saved
> > > > > state. And any working state transaction will only write to
unused
> > > > blocks,
> > > > > i.e. blocks not being used by saved state, so saved state will not
be
> > > > > touched. Does that sound perfect enough theoretically?
> > > > >
> > > > > --
> > > > > Zhongwei Wang
> > > > > Applied Data Systems
> > > > > www.applieddata.net
> > > > > Application - Ready embedded systems
> > > > > Microsoft Windows Embedded Partner
> > > > > Gold Level Member
> > > > >
> > > > >
> > > >
> > > >
> > > >
> >
> >
> >


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