I have same issue... I cant chmod, copy or vi save the file... always same message :

root@miner/home/inno_py:
cp /home/inno_py/inno_config.py ./inno_config.py.bk
cp: can't create './inno_config.py.bk': Read-only file system

Is the only option is to unmount and mount back the file system as a RW?  I am no linux expert, not sure the consequences on the A4+