Doensn't work, i got the same response read-only file system using both commands. Alternatives? Thank's!
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+
I'd imagine that route will work. I can check out the correct "safe" procedures for the A4+ to make the switch once I get home today. Unless someone is faster to help.

Thank's @kb8679
Ok, this works:
"mount -o remount,rw /dev/root /"
Once you're done, you can change it back to read only with:
"mount -o remount,ro /dev/root /"
I tested it by simply making a empty file to the same folder where the inno_config.py is located. Works just fine.
There are two partitions by default; one being the one pointed to / which is read-only. Other is for the configuration files which are rw by default.
Partition identifier: /dev/root
Mountpoint: /
Partition identifier: /dev/mtdblock5
Mountpoint: /innocfg