I made a home video player with Kodi on a RaspberryPI. I plugged in a 128GB USB key to store movies on it but found it to be dead slow. I formatted it with FAT and other than the file size limit it's veey much error prone (sometimes downloaded files are corrupted). Before that I tried ext2 (or 3) but took something like 10 minutes for it so I reverted to FAT and I didn't use it for more than fs creation.
But now after one week running, other than the errors the FS is now read-only! I still have to investigate the logs to understand why, but it seems to me FAT is not the right way for it. Before going ext2, what is the best solution?