Library /sys$common/syshlp/basichelp.hlb Run time errors, FATSYSIO_  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Fatal system I/O failure (ERR=12)

  An I/O error has occurred in the system or Record Management Services.
  The  last  operation  will  not  be  completed.   See  the OpenVMS RMS
  documentation for RMS errors or retry the operation.