read only file system - not by design

[Steven Stern]

As I was typing away a few minutes ago on an FC3 machine back a the office, it
suddenly said "read only file system" and refused to write anything. After a
few minutes of poking around, I rebooted. The machine has not come back up.

For when I get in tomorrow: What's the most likely cause of a file system
suddenly going read only?
-- 
  Steve