RECOVER[/RMS_FILE] {/FORWARD|/BACKWARD} recovery-filespec

  Invokes the RMS Recovery Utility.  Applicable only if you have the
  RMS Journaling option.  See the VAX RMS Journaling Manual.

  The RMS Recovery Utility (RECOVER/RMS_FILE) is used to restore RMS
  files after the files have become lost or the data in them has
  become unuseable. You can use RECOVER/RMS_FILE to redo operations
  (with after-image journaling, using a previously-made backup file),
  or to undo operations (with before-image journaling, using the
  actual data file). When you use the RMS Recovery Utility to redo
  operations by rolling an RMS file forward from a backup copy of the
  object file, it is called after-image recovery.  When you use the
  RMS Recovery Utility to undo operations by rolling the object file
  back to a previous state, it is called before-image recovery.

  You invoke the RMS Recovery Utility by typing the command
  RECOVER/RMS_FILE and the appropriate qualifiers.

Additional information available:

Parameters

/BACKWARD/BI_BUFFER_SIZE/CACHE_SIZE/FORWARD
/JOURNAL/LOG/UNTIL

  The only parameter is the file specification to which recovery is
  applied.  For recovery using after-image journaling, use the backup
  copy of the data file as the file specification. For recovery using
  before-image journaling, use the original data file as the file
  specification.

  The /BACKWARD qualifier instructs the RMS Recovery Utility to roll a
  file backward to a previous state.  Use the /BACKWARD qualifier to
  recover a file using a journal file that has before-image journal
  entries for the data file that you specify.

  To specify a date and time to which the file is to be rolled
  backward, use the /UNTIL= qualifier.  You should always use this
  qualifier for before-image recovery; if you do not use the /UNTIL=
  qualifier when you specify /BACKWARD, the file will automatically be
  rolled back to the time when the first entry was made in your
  before-image journal.

Additional information available:

Examples

  $ RECOVER/RMS_FILE/BACK/LOG/UNTIL=30-JUN-1988 WEEKLY.DAT
  %RMSREC-I-FILBACKWARD, $DISK1:[PAYROLL]WEEKLY.DAT;17 rolled
  backward
  %RMSREC-I-DATETIME, date/time of last record processed: 30-JUN-1988
  07:41:23.27
  %RMSREC-I-NUMRECS, 936 records processed

  This command rolls the file WEEKLY.DAT backwards until 30 June 1988
  (default time of day of 00:00).  The /LOG qualifier instructs the
  RMS Recovery Utility to display display the number of records
  processed processed (that is to say, un-done) and the date and time
  that the last record was written. After executing this command, the
  file WEEKLY.DAT is the same as it was at midnight, 30 June 1988.

  The /BI_BUFFER_SIZE= qualifier lets you specify the number of blocks
  that RMS recovery reads for each I/O from the journal file.  It is
  similar in concept to the multiblock count field (RAB$B_MBC) in RMS.

  Use the /BI_BUFFER_SIZE qualifier to tune your application and
  improve performance during recovery.  For more information on how to
  tune your application using this value, see the Designing
  Files/Units of Input/Output section in the Guide to VAX/VMS File
  Applications) and the VAX RMS Reference Manual.

  You can use the /BI_BUFFER_SIZE qualifier only when you specify the
  /BACKWARD qualifier.

Additional information available:

Examples

  $ DIRECTORY/SIZE ACCOUNTS_PAYABLE.RMS$JOURNAL

  ACCOUNTS_PAYABLE.RMS$JOURNAL;1      108

  $ RECOVER/RMS_FILE /BACKWARD /BI_BUFFER_SIZE=108  ACCOUNTS_PAYABLE.DAT

  This example shows that the journal file ACCOUNTS_PAYABLE.RMS$JOURNAL
  has a size of 108 blocks.  The RECOVER/RMS_FILE /BI_BUFFER=108 command
  sets the buffer to be 108 blocks.

  The cache size is the number of indexed buckets that are retained in
  in-memory cache during a recovery operation. Use the /CACHE_SIZE=
  qualifier to set the size of a cache in order to improve performance
  when recovering indexed files.  In general, the performance of the
  recovery operation improves as the cache size grows larger.
  However, other system considerations could affect the ideal size.

  The /CACHE_SIZE= qualifier is similar in concept to the multibuffer
  count field (RAB$B_MBF) in RMS.  For more information on how to tune
  your application using this value, see the Guide to VAX/VMS File
  Applications and the VAX RMS Reference Manual.

  The /CACHE_SIZE= qualifier applies only to indexed files.  You can
  use this qualifier with either /BACKWARD or /FORWARD recoveries.

  The /FORWARD qualifier instructs the RMS Recovery Utility to roll a
  file forward from a previous state.  Use the /FORWARD qualifier to
  recover a backup file by using the after-image journaling
  information contained in a journal file.  Both the journal file and
  a backup copy of the data file must be available in order to recover
  a file using the /FORWARD qualifier.

Additional information available:

Examples

  $ RECOVER/RMS_FILE/FORWARD/LOG BACKUP.DAT
  %RMSREC-I-FILFORWARD, $DISK1:[PAYROLL]BACKUP.DAT;17 rolled forward
  %RMSREC-I-DATETIME, date/time of last record processed:  4-AUG-1988
  11:28:29.74
  %RMSREC-I-NUMRECS, 3490 records processed

  This command rolls the file forward, beginning at the point when the
  last backup was made (using the BACKUP/RECORD command) and
  continuing through the last record that was written to the journal
  file.  At this point, the recovered file has the same data as the
  data file (on 4 August at 11:28), with the file characteristics of
  the backup file.


  $ RECOVER/RMS_FILE/FORWARD/UNTIL=30-JUN-1988/LOG WEEKLY_BACKUP.DAT
  %RMSREC-I-FILFORWARD, $DISK1:[PAYROLL]WEEKLY_BACKUP.DAT;17 rolled forward
  %RMSREC-I-DATETIME, date/time of last record processed: 29-JUN-1988
  15:23:44.30
  %RMSREC-I-NUMRECS, 2554 records processed

  This command rolls the file WEEKLY_BACKUP.DAT forward, beginning at
  the time that the file was created by the Backup Utility.  It is
  rolled forward until 30 June 1988, using the default time of day
  00:00.  (In this case, the last record written before that time was
  on 29 June at 15:23.)  Use of the /LOG qualifier provides information
  about the number of records processed and the date and time of the last
  record that was restored. After this operation, the file WEEKLY_BACKUP.DAT
  is the same as the data file for which it was the backup copy
  (presumably, WEEKLY.DAT) at midnight on 30 June 1988.

  The /JOURNAL= qualifier specifies the name of the journal file that
  is to be used for recovery operations. During the recovery
  operation, the entries in this journal file will be applied to the
  backup file (for after-image recovery) or to the data file (for
  before-image recovery). By default, the RMS Recovery Utility uses
  the journal file that was specified when the data file was marked
  for journaling (with SET FILE/AI_JOURNAL or /BI_JOURNAL).

  You might use the /JOURNAL qualifier if the journal file were in a
  different location from that originally specified in the SET FILE
  command (for example, if the original journal file becomes unuseable
  and a backup copy of the journal file is on another device). You
  might also use the /JOURNAL qualifier if the journaling information
  were in two or more different journals.

Additional information available:

Examples

  $ RECOVER /FORWARD /JOURNAL=ARCHIVE_DISK:INVENTORY_1  INVENTORY.BCK
  $ RECOVER /FORWARD /JOURNAL=ARCHIVE_DISK:INVENTORY_2  INVENTORY.BCK
  $ RECOVER /FORWARD INVENTORY.BCK

  In this example, three after-image journal files are applied to the
  file INVENTORY.BCK, which would be a backup copy of a data file. In
  the third of the RECOVER commands, where the /JOURNAL qualifier is
  not used, the default journal file (the one specified by the most
  recent SET FILE/AI_JOURNAL command for the data file) is used.
  (Note that this series of commands would not be necessary if a
  backup copy of the data file were made and is still available when
  the most recent SET FILE command was issued.)

  Use the /LOG qualifier to generate a report of the recovery
  operation. When you use the /LOG qualifier, the RMS Recovery Utility
  displays the number of records that were processed during the
  recovery operation, and the date and time of the last record that
  was processed (recovered).

  The /UNTIL= qualifier specifies the date and time at which to end an
  after-image or before-image recovery. Specify the date and time
  using either absolute time or delta time.  See the DCL Concepts
  Manual for more information about specifying absolute and delta
  time.

  For after-image recovery, the /UNTIL qualifier specifies the date
  and time up to which the backup copy of the data file is to be
  restored. If you do not use the /UNTIL qualifier with after-image
  recovery, then all updates through the most recent update recorded
  in the after-image journal file are restored.

  For before-image recovery, the /UNTIL qualifier specifies the date
  and time back to which the data file is rolled.  That is, all
  modifications to the data file from the present time to the time
  specified with the /UNTIL qualifier are removed.  In most cases, you
  should use the /UNTIL qualifier with before-image recovery;  if you
  do not, then all modifications recorded in the before-image journal
  file will be removed.

Additional information available:

Examples

  $ RECOVER /BACKWARD /UNTIL=19-JUL-1988:12:00  SALES.DAT

  This command rolls the file SALES.DAT backward, beginning with the
  most recent update and continuing in reverse chronological order
  until 12:00 noon on July 19, 1988.  The Recovery Utility
  automatically uses the before-image journal file that was specified
  (or implied) with the most recent SET FILE/BI_JOURNAL command for
  the file SALES.DAT.