Copies files, saves files on save sets, restores files from save sets,
lists files on save sets, and compares files with other files or save
sets.

Format
 BACKUP input-file-spec,... [output-file-spec,...]

Additional information available:

ParametersQualifiers

input-file-spec
 Specification of a file to be copied or saved, or a save set to be
 restored.  Wildcard characters are allowed in the specifications of
 regular files, and in those of save-set files on magnetic tape.
 DECnet node names are allowed only in save-set file specifications.
output-file-spec
 Specification of a file to be created by a copy or restore operation,
 or a save set to be created by a save operation.  Wildcard characters
 are allowed for normal files.  No wildcard characters are allowed for
 save sets.  DECnet node names are allowed only in save-set file
 specifications.

Additional information available:

/BACKUP/BEFORE/BLOCK_SIZE/BRIEF/BUFFER_COUNT
/COMMENT/COMPARE/CONFIRM/CRC/CREATED/DELETE
/DENSITY/EXCLUDE/EXPIRED/FAST/FULL/GROUP_SIZE
/IGNORE/IMAGE/INCREMENTAL/INITIALIZE/INTERCHANGE
/JOURNAL/LABEL/LIST/LOG/MODIFIED/NEW_VERSION
/OVERLAY/OWNER_UIC/PHYSICAL/PROTECTION/RECORD
/REPLACE/REWIND/SAVE_SET/SELECT/SINCE/TRUNCATE
/VERIFY/VOLUME

 /CREATED
 /EXPIRED
 /MODIFIED (default)
 Qualifies input files.
 Selects files for the backup operation according to the dates of their
 most recent backups, their creation dates, their expiration dates, or
 the dates of their last modifications. Relevant only with the /BEFORE
 and /SINCE qualifiers.

 Qualifies input files.
 Processes only those files dated earlier than the specified time,
 which can be an absolute time or one of the following keywords:

 +-----------+----------------------------------------------+
 | BACKUP    | The date recorded by a previous              |
 |           | BACKUP/RECORD; available only on Files-11    |
 |           | Structure Level 2 volumes.                   |
 +-----------+----------------------------------------------+
 | TODAY     | The current day at 0 hours.                  |
 +-----------+----------------------------------------------+
 | TOMORROW  | TODAY plus 24 hours.                         |
 +-----------+----------------------------------------------+
 | YESTERDAY | TODAY minus 24 hours.                        |
 +-----------+----------------------------------------------+

 Qualifies output save sets.
 Defines the block size, in bytes, for data records in a BACKUP save
 set.  The acceptable range for n is 2048 through 65,534.  If you do
 not specify this qualifier, the default blocking size for a disk save
 set is 32,528 bytes; for a magnetic tape save set, 8464 bytes.

 /FULL
 Lists a brief amount of information on each file saved or restored
 (specification, size, and creation date), or lists the information in
 the format of the DIRECTORY /FULL command.  Relevant only when the
 /LIST qualifier is also specified.

 Specifies the number of I/O buffers to be used in the backup
 operation. The maximum value is 5; the default is 3.  Relevant with
 both disks and magnetic tape.

 Qualifies output save sets.
 Places the comment in the save set. The comment is displayed in list
 operations. If the comment contains spaces or special characters,
 enclose it in quotation marks (").

 Compares two files, two groups of files, or a save set and a file or
 group of files. In the latter case, the save set must be specified as
 the first parameter. The default version number is *, which processes
 all versions of the file.

 Qualifies input files.
 For each file being copied or saved, displays a query to which you
 must respond Y to copy the file -- any other response skips the copy
 or save operation for that file.

 /NOCRC
 Qualifies input and output save sets.
 Performs the Cyclic Redundancy Check on save-set data.

 See /BACKUP.

 Deletes input files after they are saved.

 The /DENSITY qualifier is not applicable to the TK50 tape device.

 Specifies the density at which a magnetic tape save set is recorded.
 Use a value that is supported by the magnetic tape drive.  If you do
 not specify the /DENSITY qualifier, the default density is the current
 density of the magnetic tape drive.

 Qualifies input files.
 Excludes the specified files from the copy or save operation.  No
 device names are allowed.  Wildcard characters are supported for file
 specifications.  However, you cannot use relative version numbers to
 exclude a specific version.

 See /BACKUP.

 Requires write access to [0,0]INDEX.SYS on the volume containing the
 files being saved, or the volume must be write-locked.
 Uses a fast file scan. The /FAST qualifier is ignored if used with the
 /IMAGE qualifier.

 See /BRIEF.

 Qualifies output save sets.
 Defines the number of blocks to be placed in each redundancy group.
 Using the redundant information, 1 "uncorrectable" read error in
 each redundancy group can be corrected. The value must be from 0
 through 100; the default is 10; 0 means no redundancy blocks are
 written.

 Overrides restrictions placed on files. Possible keywords are:

 +-----------+----------------------------------------------+
 | INTERLOCK | Processes files that otherwise could not be  |
 |           | processed because of  file access            |
 |           | conflicts, specifically files currently      |
 |           | open for writing.   Requires SYSPRV          |
 |           | privilege.                                   |
 +-----------+----------------------------------------------+
 | NOBACKUP  | Saves or copies the contents of files that   |
 |           | are marked with the  /NOBACKUP qualifier of  |
 |           | the SET FILE command.                        |
 +-----------+----------------------------------------------+

 Requires write access to [0,0]INDEXF.SYS and [0,0]BITMAP.SYS on the
 volume being processed, or the volume must be write-locked.
 Copies, saves, or restores an entire volume. The output volume must be
 mounted /FOREIGN. The file specification parameters must consist only
 of the disk names. In save and copy operations, other file
 specification qualifiers are not allowed.

 Restores an incremental save set to a disk volume. The output file
 specification must consist only of the device name. The /INCREMENTAL
 qualifier assumes /OWNER_UIC=ORIGINAL, and can be used only on
 Files-11 Structure Level 2 volumes.

 /NOINITIALIZE (default for sequential disk volumes)
 Initializes the output volume (in an image copy or a save operation).
 An image copy operation uses the volume initialization data on the
 input volume. Any existing data on the volume is lost.

 Do not use except where explicitly instructed.
 Does not copy access control lists or directories not selected as
 files.  Block size on magnetic tape is limited to 8192 bytes.  Magnetic
 tapes are written using normal error recovery to eliminate bad records
 on the resulting magnetic tape.

 Maintains a record of save sets, times of creation, and contents. When
 /JOURNAL is specified during a save operation, information concerning
 the operation is appended to the specified file. A new file is created
 if the specified file does not exist. The file specification defaults
 to SYS$DISK:BACKUP.BJL. Used with /LIST, the /JOURNAL qualifier
 displays the contents of the journal. The /BEFORE and /SINCE
 qualifiers, when used with /JOURNAL /LIST, refer to the time at which
 the save set (not saved files) was created.

 Qualifies output file-specs.
 Specifies the volume label for a save set written on magnetic tape
 or sequential disk.  For save sets written on tape, you must use a
 string of 1 to 6 alphanumeric characters.  For save sets written  on
 sequential disk volumes, the string must be 1 to 12 alphanumeric
 characters.

 If you do not specify the /LABEL qualifier, label will be derived
 from the save-set name.  In a multivolume disk save set, the volume set
 name will be the save-set name.  The label of each volume in the volume
 set will be the label string or the label string derived from the save-set
 name and followed by a two-digit volume number, starting with 01.

 If you specify a list of labels, BACKUP will label save-set volume n with
 label n in the list of labels.  If the list of labels is shorter than the
 number of volumes in the save set, BACKUP will generate labels for the
 remaining volumes using the first label in the list followed by a two-digit
 relative volume number.  Note that for magnetic tape save sets, the volumes
 are counted, starting (at 01) with the tape on which the current save set
 started.  Magnetic tape volume numbers are not maintained across multiple
 save sets written on multiple magnetic tapes.

 Lists information on the contents of a save set. The listing is
 written to file-spec, which defaults to SYS$OUTPUT. This qualifier can
 stand alone, in which case the first and only parameter must be the
 name of the save set; or the qualifier can be part of a save or
 restore operation, in which case the listing reflects the status of
 the save set after completion of the operation. Do not use /LOG with
 /LIST when the output is directed to SYS$OUTPUT.

 /NOLOG (default)
 Displays on SYS$OUTPUT the name of each file as it is processed.

 See /BACKUP.

 Qualifies output file-spec.
 Creates a new version of a file if you attempt to restore or copy a
 file to a directory that has a file of the same name and version-number
 Files are processed in decreasing version-number order and created in
 ascending order, so that version numbers are inverted.  Results are
 unpredictable if /NEW_VERSION is used with /COMPARE or /VERIFY.

 Qualifies output files.
 Overlays the named existing file rather than allocating new space for
 the file.

 Positional.
 Requires SYSPRV privilege or ownership of the UIC to specify
 with an output file or save set.
 As an input file qualifier -- Processes only files owned by the
 specified UIC. A specification of /OWNER_UIC without a value means
 your process UIC.

 As an output file qualifier -- Resets the ownership of the copied or
 restored file. You can specify a UIC or one of the following keywords:

 +----------+-----------------------------------------------+
 | DEFAULT  | Your process UIC                              |
 +----------+-----------------------------------------------+
 | ORIGINAL | Existing UIC of the saved file                |
 +----------+-----------------------------------------------+
 | PARENT   | The UIC of the directory under which the file |
 |          | is being restored                             |
 +----------+-----------------------------------------------+

 If no /OWNER_UIC is specified, then it is the same as specifying
 /OWNER_UIC=DEFAULT. A /OWNER_UIC specification without a value means
 ORIGINAL.

 As an output save-set qualifier -- Specifies ownership of the save
 set. The default is your process UIC.

 Ignores any file structure on the volume. Output disks must be the
 same type as input disks; output disks cannot have a bad block where
 input disks do not. A save set written using /PHYSICAL can only be
 read as a physical save set. Output disks must have been mounted
 /FOREIGN; input disks must have been mounted /FOREIGN or the user must
 have LOG_IO privilege. The file specification for a physical volume
 can contain only a device name. Note that this should only be used on
 input and output disks proven to have no bad blocks.

 Qualifies output save sets.
 Specifies protection for a save set. Specify ownership as SYSTEM,
 OWNER, GROUP, or WORLD. Specify access as R, W, E, or D. Default
 protection is that of the current process.

 Requires ownership of the file or SYSPRV privilege.
 Records in the file header the backup date for each file processed.
 Valid only for Files-11 Structure Level 2 volumes.

 Qualifies output files.
 Deletes the existing output file and creates a new file if you attempt
 to restore or copy a file to a directory that has a file of the same
 name and version number.

 /NOREWIND (default)
 Causes the input tape reel to be rewound (/REWIND)  or  not  rewound
 (/NOREWIND) to beginning-of-tape (BOT) before BACKUP searches for
 the save-set name specified in the input-file-spec.  Use this qualifier
 only for magnetic tape save sets.

 Qualifies input and output save sets.
 Identifies the file specification as a save set, not a normal file.
 This qualifier is required for save sets on disk.

 Qualifies input save sets.
 Restores only the specified files. Wildcard characters are allowed. No
 device names are allowed.

 Qualifies input files.
 Selects for the append operation only those files dated after the
 specified time. You can specify time as an absolute time or as one of
 the following keywords:

 +-----------+----------------------------------------------+
 | BACKUP    | The date recorded by a previous              |
 |           | BACKUP/RECORD                                |
 +-----------+----------------------------------------------+
 | TODAY     | The current day at 0 hours                   |
 +-----------+----------------------------------------------+
 | TOMORROW  | TODAY plus 24 hours                          |
 +-----------+----------------------------------------------+
 | YESTERDAY | TODAY minus 24 hours                         |
 +-----------+----------------------------------------------+

 /NOTRUNCATE (default)
 Truncates a sequential output file at end of file when creating it
 during a copy or restore operation. By default, a copy or restore
 operation uses the allocation of the input file to determine the size
 of the output file.

 Verifies data transfers. On file structured copy operations, /VERIFY
 compares each file after it has been copied. On physical copy
 operations, /VERIFY compares the volume after it has been copied. For
 save or restore operations, /VERIFY compares in a separate pass.
 Incompatible with the /NEW_VERSION qualifier.

 Processes a specific disk volume in a disk volume set. Valid only with
 the /IMAGE qualifier. The /VOLUME qualifier requires only n+1 drives
 (rather than 2*n); during a copy or save operation the entire set must
 be write-locked for consistent results. In save operations the save
 set contains the segments of the files located on the specified
 volume. The input volume set must be fully mounted. The save set can
 be restored only with the /VOLUME qualifier. In restore operations the
 output volume is a functionally equivalent copy of the selected
 relative volume. In restore operations the input save set must have
 been created using the /IMAGE qualifier. The input save set can be
 either an image save set of a full disk volume set or a selected
 volume save set created with the /VOLUME qualifier. You cannot use the
 /NOINITIALIZE qualifier in a restore operation with the /VOLUME
 qualifier. In a selected volume-compare operation between two disk
 volume sets, both volume sets must be fully mounted.