Hi Reto, Mr. Jukka just opened a PR that could help the issue related to the cluster issue:
https://github.com/apache/incubator-nuttx/pull/3740 When you face an issue with the SDCard a good idea is to do a raw copy of it on Linux using the dd command, then you could duplicated the issue later. If you find an easy way to reproduce the issue, it will make it easier for other people duplicate your issue and help to debug it. BR, Alan On 5/18/21, Reto Gähwiler <gret.hexa...@gmail.com> wrote: > Dear All, > > First of all, in case a similar thread pops-up authored by myself, please > ignore. > > Recently we discovered some issues with the FAT32 partition on the SD-Card > used in our device running on nuttx. There are actually a bunch of issues > we are strugle to understand related to the filesystem. > The issue discovered recently is, that a statfs call won't return the true > number of free clusters. It rather returns what ever is in the FS INFO > section of the FAT32 partition. Inserting such a "corrupted" card into an > SD-Card reader and mounting it to Windows shows following: > > #1 Windows file explorer reports the correct free space. > #2 Comparing the free space in file explorer and looging at FS INFO section > with "Active - Disk Editor" doesn't line up. Windows wouldn't write any > longer the FS INFO section on that card. Even if all the files/dires are > wiped from the card. > #3 Whenever files are added / removed under nuttx the FS INFO section would > be updated by nuttx, but to the wrong number since the base is wrong. > #4 Mounting the card to linux and properly unmount it might actually fix > the issue. But not always! > #5 Quick format the card resolved the issue too. Windows would once again > write the FS INFO section and nuttx would shows the correct free space. > #5 Running a "chkdsk /f" under windows on that broken SD-Card fixes the > issue too. Reporting a broken file in a root folder on that card. > > We indeed had issues with corrupted files in the past. Usually in the > logging directory, which is accessed most. How they corrupt we do not know. > The corruption is recognised in the following ways: > > #A cryptic and too long file names, we only make use of short file names > (8.3) > #B files whcih became folders > #C sizes which are not possible > #D combinations of the above > > Our application supervises the SD-Card with statfs and removes files once > we hit a quota of 0.85. Therefore, the card is not filling up. However, the > most recent recognition of this behvaiour was due to an application bug > which allowed the card to fill up under some circumstances. > Playing around with a quickformated SD-Card, filled up with data and trying > to retrigger the issue revealed that I never get the ENOSPC but only EIO > once the card is full! But never managed to get the statfs issue. > For the logging we use the fstream family (fopen, fwrite, fread, fflush, > fsync) commands. For config files and other things also the low level > read/write are used. > > One more thing, among all the logging files we once in a while have > corrupted file content. Typically that is a skipped byte or doubled byte > (we use protobuf and can see that encoding the binary). This seems to > happen during reading but also writing the file. > > At the moment we didn't investigate the fat driver of nuttx but rather > tried to analyse the problem. And now we have a bunch of question marks. > > #1 Has anyone recongised similar issues? > #2 Does anyone know a tool which can be used in nuttx equivalent to chkdsk > under windows? Or do quick format? > #3 Why is there no ENOSPC but EIO once the card is full? > #4 What triggers the corrupted files? How robust is the nuttx FAT32 > considering stackdumps and powerlosses? > > For the purpose of investigation, I have an image of the SD-Card when it > was in the state of reporting wrong sizes in nuttx. > > Looking forward to your answers and ideas. Appreciate your help, > > Reto >
