Error handling

SAVE/EXPORT runs

• Write errors
  In the event of an unrecoverable error when writing to a tape or MT cartridge, ARCHIVE issues message ARC0701 at the console and on SYSOUT. ARCHIVE then attempts to continue the save run without data loss or skips the errored file and continues the save run.
  If, however, the end-of-file identifiers cannot be written, the entire save run is aborted. An error-free restoration run cannot be performed with such a tape or MT cartridge.

• Read errors
  If an error occurs during a tape-to-tape save (copying of save tapes or MT cartridges) when the input tape is being read in, the copying of the file and the run are continued. The error is reported by means of appropriate messages at the console and on SYSOUT.

RESTORE/IMPORT runs

The handling of read or format errors and open errors varies in accordance with specifications in the OPERATOR operand of the PARAM statement.

OPERATOR=NO	In the event of a read or format error, ARCHIVE implements default error handling.
OPERATOR=YES	A message is output at the console in the event of a read or format error during restoration. The following responses are possible: tsn.0 ARCHIVE implements default error handling (standard routine). tsn.1 ARCHIVE implements a special error handling routine.

Open errors (tape labels cannot be read)

• Standard routine
  If OPERATOR=NO was specified, the tape is skipped and the run resumed with the next tape. Any file which could not be restored completely bears an identification to this effect in the ARCHIVE report.

• Special routine
  If the response tsn.1 is given to the message ARC0903, the system tries to open the magnetic tape or MT cartridge again, although this time with LABEL=NO (overriding the volume label).

  • If this is possible, the restoration run is continued.

  • If this is not possible, the tape or MT cartridge is skipped. One or more messages for device errors are then output on the console, and the operator must respond to these with tsn.1.

This method of error recovery is, for data security reasons, only possible under the user ID of systems support. TPIGNORE=YES must be set in the user catalog.

Read or format errors during restoration

• Standard routine
  Restoration of the file to be written back is aborted and the file in question is marked appropriately in the ARCHIVE report. The ARCHIVE run is continued from the next file which can be read.
  Partially saved files are always handled in this way.

• Special error handling routine
  If OPERATOR=YES is specified in the PARAM statement, and if the messages ARC0901 (read error) and ARC0902 (format error or incorrect block number) are responded to with tsn.1, then ARCHIVE resumes restoration of the appropriate file.

  If the message ARC0906 (incorrect block number) is responded to with tsn.1, ARCHIVE continues processing of the appropriate tape. If read or format errors occur, then ARCHIVE enters a dummy block in the first PAM page of the series of PAM pages which cannot be read. The following text appears at the start of the dummy block:

  *****ARCHIVE RESTORE DUMMY BLOCK*****

  • In the case of files with PAM keys (BLOCK-CONTROL-INFO=PAMKEY), the other PAM pages of this series are not written and therefore have a different internal file name (coded file ID, CFID) from the restored file.

  • In the case of files without PAM keys (BLOCK-CONTROL-INFO=NO/WITHIN-DATA-BLOCK) each unreadable PAM page is replaced by a DUMMY block.

  Restoration of the file then continues from the next readable block.

An invalid block number causes all PAM pages to be restored from the save file. The printout of the ARCHIVE save file concerning the environment of the particular block lists any PAM pages that are missing from the file.

If more than 99 read or format errors occur on a tape or a MT cartridge, reading of this tape or MT cartridge is aborted. The run is resumed with the next input tape or MT cartridge.

A format error of a special type occurs when the ARCHIVE header block of a tape or MT cartridge is faulty. In this case, ARCHIVE rejects the tape or MT cartridge with message ARC0249. This is, for example, the case with tapes or MT cartridges created as continuation tapes or MT cartridges when duplicating an ARCHIVE tape or MT cartridge with a product other than ARCHIVE.