I did not know about immutable, but I have noticed that c9.io uses another way to avoid modification of a file present in a directory that I own. It makes it a

I did not know about immutable, but I have noticed that c9.io uses another way to avoid modification of a file present in a directory that I own. It makes it a read only mount point: /dev/mapper/volg1-lvdata on /home/ubuntu/.ssh/authorized_keys type ext4 (ro,relatime,data=ordered)