Description

   The SET FILE/BI_JOURNAL command marks one or more RMS files
   for before-image journaling. You can also specify certain
   characteristics of the journal with this command, including its
   file specification, whether it is to be created, its initial
   size, and its default extension quantity. The SET FILE/NOBI_
   JOURNAL command unmarks a file for before-image journaling.

   After a data file is marked for before-image journaling with the
   SET FILE/BI_JOURNAL command, the following events occur whenever
   the data file is opened by RMS for write operations:

   o  The journal is opened.

   o  All subsequent modifications to the data file are recorded in
      the journal.

   By default, the journal has the same file specification as
   the data file that is to be journaled, but with the file type
   RMS$JOURNAL. That is, if you issue the following command, then,
   by default, the file specification for the before-image journal
   is FINANCE_DISK:PAYROLL.RMS$JOURNAL:

   $ SET FILE/BI_JOURNAL FINANCE_DISK:PAYROLL.DAT

   If erroneous or corrupt data is introduced into the data file,
   you can use the RMS Recovery Utility to "roll back" the data file
   that has been marked for before-image journaling. This will allow
   you to restore the data file to a previous state by removing data
   until a specified time (prior to the introduction of bad data).

   Use the SET FILE/NOBI_JOURNAL command to unmark a file for
   before-image journaling. After you use the SET FILE/NOBI_JOURNAL
   command for a file, modifications to that data file will no
   longer be written to the journal.

   You must use the SET FILE/NOBI_JOURNAL command before you can
   delete a file that has been marked for before-image journaling.