Re: TFAT stability

So you think there is no solution to stabilize the filesystem?

"Marco Contenti" wrote:

> The problem is rather simple: if you look at how the msflash block
> driver is implemented, you can see that disk-like 512-byte sectors are
> mapped plain linearly to flash memory. Well, what if you must write a
> sector in a flash block already in use? You need to back up data
> somewhere, erase the 128k block (which can take 1 second) and restore
> the modified block content.
> All this is done in the FAL (Flash Abstraction Layer), which is not
> documented. Are we sure that FAL can recover, say, if power fails in the
> middle of a block erase?
> Note: TFAT knows nothing of flash blocks. It does safe transactions with
> 512-byte sectors.
> Using a CF card leaves the task of virtualizing 512-byte sectors out of
> a flash array to the microcontroller firmware inside the card, which is
> supposed to be heaviliy tested.
>
> Regards.
>
> Marco Contenti
> PROJECT s.a.s. (WEP)
> www.projectsas.it
> marco.contenti@<see domain above>
>
> turnsek ha scritto:
> > Thanks for the reply.
> >
> > The problem is we don't have the WinCE5.0 yet.
> > We have turned off AutoScan and the platform seems to be stable (for now).
> > We are perfoming powerdown and powerup tests for now and we'll see if it will
> > survive overnight. I shure hope so.
> > Regarding the AutoScan, I think the filesystem moust be unmounted during
> > this scan and as that is not protected from powerdowns. This might be the
> > problem during powerup. So I have removed AutoScan and we will see. I shure
> > hope so that there is no bug in the TFAT implementation or Msflash block
> > driver implementation.
> >
> > O, yes. We have another platform with WCE4.2 and SH3 processor with CF card.
> > The configuration is almost the same. TFAT filesystem is on the CF card and
> > we don't have any problems. We had similar problems with FAT filesystem, but
> > when we switched on TFAT, everything was ok. So, the problem may be in block
> > driver and not the TFAT. What do You think?
> >
> > Thanks, Jernej
> >
> >
> > "<ctacke/>" wrote:
> >
> >
> >>I've actually got an open case with Microsoft on this issue. Their first
> >>suggestion, which I'm in the process of implementing, was to take the TFAT
> >>stuff from CE 5.0 and pull it into my 4.2 platform and see if that fixes it.
> >>I'm not done yet, so I don't know if it fixes the problem, but you might try
> >>the same.
> >>
> >>-Chris
> >>
> >>
> >>
> >>"turnsek" <turnsek@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> >>news:2617B633-7B34-41D8-A06F-7035956A920A@xxxxxxxxxxxxxxxx
> >>
> >>>Yes, the flash modifying is the issue here, but why? I have tried to
> >>>remove
> >>>the registry hives from the flash to RAM and now my filesystem crushes,
> >>>but
> >>>at least the platform boot itself (ethernet is working etc.). All files
> >>>are
> >>>missing on my storage card (we are using Intel StrataFlash J3). I have
> >>>also
> >>>tried to make two partitions, both with files written to them. In normal
> >>>operation the application is only on the first patiition and all the
> >>>wriiting
> >>>and reading is done to that partiion. After crash, only files on this
> >>>partition are missing. The second one is ok.
> >>>
> >>>Do I have some registry settings wrong for the TFAT or is it something
> >>>else?
> >>>I have check the newsgroups and it seems to me that a lot of folks are
> >>>having
> >>>this kind of problems. But there is no solution proposed except for "UPS
> >>>kind" of backup during power down. This is not an option for us. Microsoft
> >>>also said that TFAT is safe and stable. Ok, there could be an issue with
> >>>the
> >>>msflash strata driver, but that is also supplied by them. So, where is the
> >>>catch? I' ve ruled out the hardware problem, because there is the
> >>>consistency
> >>>about filesystem crash. If it would be hardware then there would be
> >>>problems
> >>>with image and bootloader too and not with filesystem only.
> >>>
> >>>Thanks, Jernej
> >>>
> >>>"Bruce Eitman (eMVP)" wrote:
> >>>
> >>>
> >>>>I have also seen these failures on a few platforms, both CE 4.2 and 5.0.
> >>>>I
> >>>>think that it has a lot to do with background compaction and removing
> >>>>power
> >>>>while the flash is being modified.
> >>>>
> >>>>--
> >>>>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:A6C143B2-6D21-49DF-8F05-B5950ECE3A2A@xxxxxxxxxxxxxxxx
> >>>>
> >>>>>Hi all!
> >>>>>
> >>>>>We have PXA255 based platform with WCE42 and we are testing stability
> >>>>>of
> >>>>
> >>>>the
> >>>>
> >>>>>platform. Our hardware is not battery backed and we rely on powerdown
> >>>>
> >>>>driver
> >>>>
> >>>>>and TFAT file system. We have noticed that after number of power down
> >>>>>and
> >>>>>power up cycles (quite a lot) our platform dies. We have flash resident
> >>>>>persistent registry (hive based). Platform could not start anymore. I
> >>>>>am
> >>>>>suspecting that the file-system is corrupted (so the registry too). We
> >>>>>are
> >>>>>using msflash strata driver.
> >>>>>Our settings are:
> >>>>>
> >>>>>[HKEY_LOCAL_MACHINE\System\StorageManager]
> >>>>>"Dll"="fsdmgr.dll"
> >>>>> "PNPUnloadDelay"=dword:0
> >>>>>
> >>>>>; @CESYSGEN IF CE_MODULES_STRATAD
> >>>>>; HIVE BOOT SECTION
> >>>>>; StrataFlash block driver.
> >>>>>[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\StrataFMD]
> >>>>> "Dll"="stratad.dll"
> >>>>> "Order"=dword:2
> >>>>> "Prefix"="DSK"
> >>>>> "Ioctl"=dword:4
> >>>>> "Profile"="MSFlash"
> >>>>> "IClass"="{A4E7EDDA-E575-4252-9D6B-4195D48BB865}"
> >>>>> "MemBase"=dword:b9300000
> >>>>> "MemLen"=dword:03000000
> >>>>> "Flags"=dword:1000
> >>>>>
> >>>>>; Override names in default profile
> >>>>>[HKEY_LOCAL_MACHINE\System\StorageManager\Profiles\MSFlash]
> >>>>> "Name"="MSFLASH for STRATAFLASH"
> >>>>>"Folder"="Storage Card"
> >>>>>
> >>>>>[HKEY_LOCAL_MACHINE\System\StorageManager\Profiles]
> >>>>> "AutoMount"=dword:1
> >>>>> "AutoPart"=dword:1
> >>>>> "AutoFormat"=dword:1
> >>>>>
> >>>>>; Keep FATFS from trying to shadow \Windows
> >>>>>[HKEY_LOCAL_MACHINE\System\StorageManager\Profiles\MSFlash\FATFS]
> >>>>> "MountFlags"=dword:2
> >>>>>
> >>>>>[HKEY_LOCAL_MACHINE\System\StorageManager\AutoLoad\MSFlash]
> >>>>> "DriverPath"="Drivers\\BuiltIn\\StrataFMD"
> >>>>> "LoadFlags"=dword:1
> >>>>> "Order"=dword:0
> >>>>>
> >>>>>; END HIVE BOOT SECTION
> >>>>>; @CESYSGEN ENDIF CE_MODULES_STRATAD
> >>>>>
> >>>>>
> >>>>>; @CESYSGEN IF FILESYS_FSREGHIVE
> >>>>>; HIVE BOOT SECTION
> >>>>>[HKEY_LOCAL_MACHINE\init\BootVars]
> >>>>> "SYSTEMHIVE"="Registry\\system.hv"
> >>>>> "PROFILEDIR"="Registry"
> >>>>> "Start DevMgr"=dword:1
> >>>>> "DefaultUser"="Iskraemeco"
> >>>>> ;Causing some debugchk's in debug version,
> >>>>> ;performance monitoring tools doesn't work.
> >>>>> ;RegistryFlags"=dword:1
> >>>>>; END HIVE BOOT SECTION
> >>>>>; @CESYSGEN ENDIF FILESYS_FSREGHIVE
> >>>>>
> >>>>>[HKEY_LOCAL_MACHINE\System\StorageManager\FATFS]
> >>>>> "FriendlyName"="FAT FileSystem"
> >>>>> "Dll"="fatfsd.dll"
> >>>>> ;"Flags"=dword:00000024
> >>>>>"Flags"=dword:007C0028
> >>>>> "Paging"=dword:1
> >>>>> "EnableCache"=dword:1
> >>>>> "CacheSize"=dword:0
> >>>>> "Util"="fatutil.dll"
> >>>>>"FormatTfat"=dword:1
> >>>>>; END HIVE BOOT SECTION
> >>>>>; @CESYSGEN ENDIF CE_MODULES_FATFSD
> >>>>>
> >>>>>
> >>>>>Any help would be more then welcome.
> >>>>>
> >>>>>Thanks, Jernej
> >>>>>
> >>>>
> >>>>
> >>>>
> >>
> >>
>
.

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