df command shows zero memory for / directory - it boots and works for many things

The df command shows the / directory with zero memory available. The system boots, I can open files etc. mysqld will not start because of too little memory. httpd will start.

free -m shows memory available.


This happened once before and it corrected itself. I then removed a bunch of files not needed.

I'm trying to copy important files to cdrom. The cp command tells me it can't write to cd, because it's read only. The cd disk itself says CD RW

the mount command used by itself shows that partition as read write (rw). Could it be telling me read only because it sees no memory available?


How do I tell the server to allocate some memory shown by free -m to /?

Thanks