https://devzone.nordicsemi.com/f/nordic-q-a/46777/nrf52840-dk-usbd-msc-multiple-directories-bugWhile developing code for our custom board, we ran into a filesystem corruption issue with fatfs+qspi block device and multiple directories. We were able to reproduce the bug in the usbd_msc example in SDK 15.2 AND 15.3 using nRF52840 DK: 1. Erase qspien-USTelligent Community 13Wed, 08 May 2019 17:45:30 GMThttps://devzone.nordicsemi.com/thread/186030?ContentTypeID=1Wed, 08 May 2019 17:45:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6f816846-4349-4924-a28d-7bb95f53d34aabhipray<p>Hi Jeff,</p> <p>As far as&nbsp;my testing goes, we haven&#39;t seen any issues since changing the file allocation unit to 4096. If you can describe the steps that lead to corruption, I can try to duplicate it on my end.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/185989?ContentTypeID=1Wed, 08 May 2019 13:32:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9efe7ced-4c81-4120-b493-6554fefe8548JeffW<p>Hi abhipray,</p> <p>I have had very similar issues with a Winbond W25Q64JV (4K sectors).<br />I have since changed the file allocation to 4096, but corruption is still happening.</p> <p><br />Did this totally fix your problem?<br />Thanks,<br />Jeff</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/184733?ContentTypeID=1Wed, 01 May 2019 22:39:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a840a2ce-fef0-484d-8b93-1236c0f81bf0abhipray<p>Ok, I think it&#39;s resolved now. Changing the file allocation unit parameter in f_mkfs() to 4096 seems to have solved it. The documentation for f_mkfs() says that parameter should be n times the sector size. The MX25r6435F has a 4K sector size.&nbsp;</p><div style="clear:both;"></div>