ICL 1900 Series George 3 Operating System Commands

INCDUMP (ID)

Function

To enable certain system actions mainly associated with the dumping system to be implemented via an ordinary job.

Note: Formats 1 and 11 are the only formats which should be used directly by systems programmers and installation managers. The other formats are provided solely for the performance of basic system functions, and are only documented here for completeness.

Format

  1. INCDUMP COMPRESS
  2. INCDUMP DUMP
  3. INCDUMP NOW
  4. INCDUMP QUEST
  5. INCDUMP RETURN
  6. INCDUMP RETURN,integer
  7. INCDUMP RETURN,tape list
  8. INCDUMP REUSE
  9. INCDUMP REUSE,integer
  10. INCDUMP REUSE,tape list
  11. INCDUMP RETRIEVE

Where tape list has the format (tsn)(*MT), (tsn)(*MT),...

Forbidden contexts

NO USER
In addition, the job must be running :DUMPER, and for formats 2, 3 and 4, must also be system issued.

Execution

Format 1

This compresses all directories and the following system files:

    :MASTER.DICTIONARY
    :SYSTEM.INCINDEX
    :SYSTEM.SERIAL
    :SYSTEM.OUTPUT
    :SYSTEM.JOBLIST(/B1)
    User JOBLIST files

These files tend to become sparsely filled during normal running, thus increasing the overhead of processes that access them and the space occupied by them on backing store and dump tapes.

The relevant files are checked one at a time, and an attempt is made to compress each one found to consist of more than one block. If the number of blocks used changes as a result of compression, a message is sent to the monitoring file giving the name of the file compressed, and its old and new sizes. When all such files have been checked, a final message is output giving the total and new system file sizes.

The following points should be noted:

  1. While a file is being compressed, the amount of backing store required may be twice normal, since a spare copy is kept to avoid filestore loss over a system break. This may cause problems where large files are held on small special residences, and users are advised to de-ALLOCATE such files before the compression and to re-ALLOCATE them afterwards.

  2. It is suggested that this command is used about once a week, depending on the size of the installation and the workload in terms of filestore usage. Details of the actual size and compressed size of directories and system files are given at the end of Dumper monitoring files.

Formats 2 and 3

These cause an incremental dump to take place. With format 2 only, the job will wait until DUMPTIME minutes have elapsed, or until an operator DUMP command is issued, unless the last completed increment was not suitable for general restore.

Format 4

This is used by the job :DUMPER.Q, sometimes initiated at Early Morning Start to remind operators that certain increments are unavailable because all tapes holding them are WRONGed.

Format 5

This is used to implement the DUMP RETURN,ALL command

Formats 6 and 7

These are used to implement the corresponding form of DUMP RETURN. Format 7 is also used directly by the tape-to-tape processor.

Format 8

This is used to implement the DUMP REUSE,ALL command

Formats 9 and 10

These are used to implement the corresponding form of DUMP REUSE. Format 10 is also used directly by the tape-to-tape processor.

Format 11

This format causes the number of extant retrieves in the system to be displayed thus:

    n FILES BEING RETRIEVED

Example

INCDUMP COMPRESS

Error Messages

COMMAND BEING USED BY ANOTHER JOB
COMMAND NOT FOR GENERAL USE
PARAMETER NOT RECOGNISED
PARAMETER NEGATIVE
PARAMETER MISSING