One of our linux systems went into read-only mode. We have two read-only partitions with the system files and a read-write partition where we save the data. During boot the read-write is mounted as overlay above the read only partition.
We found out, that on one system the read-write partition suddenly was in read-only mode.
It seemed that the device would not finish boot, so we flashed our system again, then we saw the following error during boot:
print_req_error: I/O error, dev mmcblk0, sector 4202498
We flashed again and got the same error with the same sector number. We must assume that the flash is dying or dead. What we would like to know if this is rather an electrical problem or if the flash is worn due to the number of write cycles? Do you have a clue how this could be distinguished?