Rails error: Errno::EIO (Input/output error)
All of a sudden one of my apps (still under development) started throwing the error "Errno::EIO (Input/output error)", coming from different controllers, but always tripping on a 'write' command. No amount of googling turned up anything useful, but after a little digging, I realized that the offending line was using puts instead of logger.debug to spit out some tracing information. I guess Rails (2.3.2) doesn't like that and was blowing up.
Changing the appropriate lines to use logger.debug resolved it.
Hope this helps someone else save a few minutes ....