Hey Alan, Thanks for your input. See reply to Jukka. About the dd command, I am aware of and make use of it. Also the reason I could test different things with the same image :)
Greetings, Reto On 2021/05/18 20:53:39, Alan Carvalho de Assis <acas...@gmail.com> wrote: > 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 > > >
