Over the weekend, one of my backup scripts started erroring out while sending the backups offsite to an FTP server. The error message was:

200 Port command successful
150 Opening data channel for file transfer.
netout: Broken pipe
550 can't access file.

The FTP host is a Windows 2003 server running Filezilla FTP Server.

The problem was that the FTP server was actually out of disk space. Good job on the descriptive error messages guys! Another one for the “time wasted looking for answers due to developers no giving the correct information on an error” box.