Fast Dump Restore

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Innovation Data Processing


FDR is primarily an in-house tool, but it does have several applications in a user environment.

FATS (Fast Analysis of Tape Surfaces) has several specific applications, including:

  • Verifying the readability of critical or archival data tapes, to avoid read data errors at application run time. Tapes with read errors may be recovered using FATS' companion product FATAR.
  • Interfacing with its companion product FATAR to perform detailed data analysis and copying of tapes.

FATAR (Fast Analysis of Tape and Recovery) is a multi-purpose magnetic tape utility. FATAR can read any magnetic tape and can process multiple files and multiple volumes in one execution.

FATAR has many applications, including:

  • Investigating an "unknown" tape, to discover its label type, file count, DCB characteristics, etc.
  • Mapping a tape, providing a compact summary of the characteristics of all files on the tape.
  • Verifying that a tape file is properly formatted (every block is checked against its DCB information).
  • Verifying that certain data fields contain valid data.
  • Scanning a tape for read data checks, which may cause application job failures.
  • Verifying the readability of critical or archive tapes.
  • Correcting invalid data or data checks by creating a copy of the input tape(s) with the bad data corrected or dropped.
  • Creating a good copy of a tape that was not properly closed (such as during a system failure).
  • Creating a backup copy of any tape (or multi-volume set of tapes), even if multiple files exist on the tape.
  • Creating a copy of a tape with a different label type from the original (such as AL-to-SL or NL-to-SL).
  • Creating copies of tapes at higher density or on a different type of tape drive.
  • Copying FDR/ABR tapes (similar to the operation of the FDR utility FDRTCOPY) or other tapes with blocksizes over 32K.
  • Making an "image copy" (an exact bit-for-bit copy) of a tape volume.


FATAR has a flexible set of command statements entered as 80-character records, of which only columns 1-71 are used by FATAR. For many operations, the commands required are very simple since the default operations of FATAR are designed to handle the most common user requirements. However, the FATAR statements allow you to greatly modify FATAR operation, including the ability to specify an operation down to a specific block and record on the tape if required.

Unless you instruct it otherwise, FATAR will read all files on the tape volume (or multi-volume tape set) specified on its TAPEIN DD statement. If DCB information is available (from JCL or from the tape labels), FATAR will deblock each tape block into individual records if the record format is fixed or variable, allowing you to examine or modify each logical record. If you prefer, or if DCB information is not available, FATAR will treat each tape block as one record.

If the input data is in ASCII, FATAR will translate it to EBCDIC before processing.

Once a block has been read, FATAR offers facilities via FATAR commands to:

  • Print the block (in EBCDIC, HEXADECIMAL, or DUMP format (HEX and EBCDIC together). All or part of the block may be printed.
  • Change the length of the block (extra bytes may be added at the beginning or end of the block or both).

If the output tape DD statement TAPEOUT is present, FATAR will copy each file read from TAPEIN to the output tape. This will be an exact copy of the input, unless you request modification of one or more data blocks, or dropping of certain data blocks. You may also request that entire files be dropped from the copy.