I'm currently trying to update the network settings on an embedded Linux device. This is typically done by modifying the contents of file /opt/etc/network/interfaces. The file system mounted at /opt/ is by default RO, however, we temporarily change this to RW while we update the file contents by using the command
mount -o remount,rw /opt
I confirm that the file system has been updated to RW by looking at the contents of /proc/mounts
I believe the file system is now read-writable since I see the RW letters.
However, when I go to modify the file, I get a read-only error.
This confuses me. The file system is read-write per /proc/mounts, however, I'm still getting a file system error. I'm not a file system master, but I have three theories of what's going:
- The storage device has some sort of memory lock (i.e. switch) enabled.
- This file actually lives in a nest file system, so it's not actually hosted on /opt
- I'm a dummy and am missing something obvious.