Check if Linux File system is Read-Only
If you for some reason think your Linux File System is read-only. Donot trust on the mount command, as it will show you your FS in rw mode.
Following command will show you the Read-Only mounted File Systems:
egrep " ro,|,ro " /proc/mounts
A File System can becom Read-Only if it has been away to lang for the OS. To prevent data Corruption, Linux makes it RO.