Failed to mount system device or resource busy. . Sep 23, 2021 · Your system is F*d because partitions of /dev/sda and /dev/sdc are mounted on the same mountpoints. @Mediterran81 The solution is using the old mount point OR unmounting the old one. I am not sure what was the problem. Try with ext4 or f2fs. Jul 5, 2019 · Why are you formatting /system and /vendor with FAT? That won't work, Android requires a filesystem aware of UNIX permissions. Instead, it is the xiaomi recovery. What am I doing wrong? EDIT: Eventually, I could format data and install the ROM. I don't get it, as it used to work. If you open a terminal you can get a list of mounted filesystems by running mount without arguments.