Overview

A BLPack Backup Tape stores a BLPack Archive File which contains copies of A-Series files in an encoded format. The Archive File is a container, and while it is usually on Tape, it may also be copied as a Disk file using a utility such as *SYSTEM/DUMPALL.

CopyWrite can access the files in an Archive File which is either on Tape or on Disk.

Copying Files from an Archive File on Tape

• Files are copied using the COPY or ADD statements in WFL,  and specifying the attributes HOSTNAME=LOCAL and  FAMILYOWNER=BLPACK. A COPY statement copies a file and overwrites an existing file with the same name. An ADD statement copies a file only if no file with the same name already exists.
• For Example, COPY *= FROM BLPACKCOPYTAPE(TAPE,HOSTNAME=LOCAL, FAMILYOWNER=BLPACK);
• Files may be copied with a different filename, using the COPY <filename> AS <filename> syntax of WFL.
• Where there are multiple files with the same name in an Archive File, a specific version may be selected using the #<fileno> syntax of Library/Maintenance enclosed in single quotes. For example, '#1'. A file selected in this way is copied with it's original filename, unless an AS <filename> part is specified.
• Files may only be copied TO a Disk or Pack.
• A BLPack Tape may be verified by copying the files to a Pack called NULL. 
  For Example:
  COPY*= FROM BLPACKCOPYTAPE(TAPE, HOSTNAME=LOCAL, FAMILYOWNER=BLPACK) TO NULL (PACK)
• The UNITNO attribute can be used to select a Tape Unit.
• The SERIALNO attribute can be used to select a Tape with a matching Serial Number.
• There may be multiple <source volumes> but only a single <destination volume>.
• The AUTOUNLOAD attribute may be set on a <source volume> to control automatic unloading of a Tape. If not specified, the value  AUTOUNLOAD=OFF is set.
• If the COMPRESSIONREQUESTED attribute is set on the <destination volume> all files which are copied are closed with CRUNCH. 

Displaying a Directory of Files in an Archive File on Tape

• The TT PDT MT <unitno> command of Supervisor displays a directory of files in a BLPack Archive File on a Tape.

Selecting Files in an Archive File on Tape

• The FLEX INQUIRY program can be used to select files in an Archive File on Tape, using the File Attributes of the files.
• The FILES <pattern> MT <unitno> command specifies the Archive File on Tape.
• All attributes except those which describe the current data contents, such as TOTALSECTORS and LASTRECORD are available. These attributes are not available because the file contents are not copied.

Copying Files from an Archive File on Disk

• An Archive File on Disk is another type of container which CopyWrite recognizes. Other types of container are CDROM Images and Wrapped Containers. There is no special syntax for copying from a BLPack Archive File.
• An Archive File on Disk can be created from an Archive File on Tape using a utility such as *SYSTEM/DUMPALL. For example,
     RUN *SYSTEM/DUMPALL("COPY BLPACKCOPYTAPE(TAPE) TO BLPACKCOPYTAPE(PACK)").
• Files are copied from an Archive File on Disk using the COPY or ADD statements in WFL, and specifying the attributes KIND=CD,HOSTNAME=LOCAL and LOCKEDFILE. The title of the Archive File is the <source volume> name, which may be changed by label equation. See the section on CD-ROM Containers for more information.
• For Example, COPY *= FROM BLPACKCOPYTAPE(CD,HOSTNAME=LOCAL,LOCKEDFILE).
• Files may be copied with a different filename, using the COPY <filename> AS <filename> syntax of WFL.
• Where there are multiple files with the same name in an Archive File, a specific version may be selected using the #<fileno> syntax of Library/Maintenance enclosed in single quotes. For example, '#1'. A file selected in this way is copied with it's original filename, unless an AS <filename> part is specified.
• Files may only be copied TO a Disk or Pack.
• There may be multiple <source volumes> but only a single <destination volume>.
• An Archive File on Disk may be a copy of the file as it existed on Tape, which is a BLOCKSTRUCTURE=FIXED, FRAMESIZE=48.
• It may also be the same file but with FILESTRUCTURE=STREAM,BLOCKSTRUCTURE=FIXED,FRAMESIZE=8 file, as created by a binary FTP of the original file. Hence, an Archive File can be copied from Tape to Disk, then binary FTPed to another system, then copied back to the A-Series, and CopyWrite will still recognize it as an Archive File. This support is provided so that Archive Files can be stored on  CD-ROM and DVD.
• If the COMPRESSIONREQUESTED attribute is set on the <destination volume> all files which are copied are closed with CRUNCH. 

Displaying a Directory of Files in an Archive File on Disk

• The TT PDT IN <filename> command of Supervisor displays a directory of files in the BLPack Archive File specified by the <filename>.

Selecting Files in an Archive File on Disk

• The FLEX INQUIRY utility can be used to select files in an Archive File on Disk, using the File Attributes of the files.
• The FILES <pattern> IN <filename> command specifies the Archive File on Disk.
• All attributes except those which describe the current data contents, such as TOTALSECTORS and LASTRECORD are available. These attributes are not available because the file contents are not copied.

MCP and BLPack File Attributes

• If CopyWrite discovers an unexpected attribute value when copying a file from a BLPack Archive File, it displays this message.
  
  WARNING: <title> BLPack Attribute[<number>] Variation Report.  Expected <value> but found <value>. Please notify  support@metalogic.eu.com.
  
• The FAB is the File Attribute Block which stores the attributes for a File on a BLPack Archive File.
• If the COPY&VERIFY command is used, then after a file is copied from the BLPack Archive File onto Disk, some of the attributes of the copied file are checked against the FAB to ensure the validity of the copied file. These attributes include DFHTOTALSECTORS, DFHEOFSECTOR and DFHLASTBITS. If there is a discrepancy between the original and the copied file, this message is displayed.
  
  Verify <title> failed on <attribute name>. File has <value> , but FAB has <value>
• The DFHTOTALSECTORS value is not checked if COMPRESSIONREQUESTED is set on the <destination volume> and the original file was not CRUNCHED.
• Please report any problems to support@metalogic.eu.com
  

Utility Functions

• CopyWrite provides some utility functions which are started by running CopyWrite as a program. If CopyWrite is run without any parameters, it displays information about the commands available.
• For example, under CANDE, U *METALOGIC/COPYWRITE, would display the syntax of the available commands.
• The general syntax for the BLPack commands is BLPACK <command> <parameters>.
• If the <filetitle> specifies a <familyname> of TAPE, then the utility attempts to open a Tape File with the given filename.

Map Command

• The Map Command reports the physical layout of the blocks and files in a BLPack Archive File on Disk.
• For example, U *METALOGIC/COPYWRITE BLPACK MAP <filetitle>

Attributes Command

• The Attributes Command reports the File Attributes of each file within a BLPack Archive File on Disk.
• For example, U *METALOGIC/COPYWRITE BLPACK ATTRIBUTES <filetitle>

TapeHeaders Command

• The TapeHeaders Command calls the FetchImageHeaders entrypoint in CopyWrite to report the title of each file within a BLPack Archive File on Disk, after the Disk File Header has been created.
• For example, U *METALOGIC/COPYWRITE BLPACK TAPEHEADERS <filetitle>

Compare Command

• The Compare Command reports the differences between two files on disk. This command can be used to check that a file recovered by BLPack is the same as a file recovered by CopyWrite. The physical file attributes are compared and for most FILESTRUCTUREs the contents are also compared.
• For example, U *METALOGIC/COPYWRITE BLPACK COMPARE <filetitle> <filetitle>

Headers Command

• The Headers Command reports the raw File Attribute Blocks of each file within a BLPack Archive File on Disk.
• For example, U *METALOGIC/COPYWRITE BLPACK HEADERS <filetitle>

Extract Command

• The Extract Command extracts a set of files from an archive and creates a new BLPack Archive File.
• For example, U *METALOGIC/COPYWRITE BLPACK EXTRACT <filetitle> FILE <file#> - <file#> AS <filetitle>

BLPack Archive Files on Windows 2000

• The Volume Directory program provided with CopyWrite for NT can be used to display a File Directory of the files on a BLPack Archive File which is on a Windows 2000 system.
• An Archive File can be copied from an A-Series to a Windows 2000 system using binary FTP. For example, COPY [FTP] BLCOPYTAPE(FTPTYPE=IMAGE) TO DISK(HOSTNAME=<hostname>,USERCODE=<usercode>).