ICL 1900 Series George 3 Operating System Commands

DUMP (DU)

Function

1. Initiates a dump, or controls tape selection for a second or subsequent increment in a dumping session
2. Requests details of current and spare tapes that may next be used by Dumper, and of any stored DUMP commands
3. Releases obsolete dump tapes for re-use by Dumper, or to the pool

Format

1. DUMP (tsn₁),(tsn₂),...SPARE,POOL,TOTAL
   The parameters may appear in any order, and all are optional. If no parameters, other than TOTAL, are supplied, decisions made on whether to continue using the current tapes, and, if not, which tapes to use instead are controlled by the way the installation manager has used the restore-time macros DTFILEINC, DTRESTINC, DTAFTERREST and NEWDTPOOL.
   
   The tsns if present specify particular tapes to be used for dumping the next increment. Any in excess of the value of installsation parameter DUMPTAPES will be ignored. The tsns must specify spare or current non-TAPEWRONGed :DUMPER.GEO3DUMPTAPEs.
   
   SPARE indicates that tapes needed beyond any explicitly specified by tsn should be spare :DUMPER.GEO3DUMPTAPEs if available, and if not from the pool. POOL indicates they shoould come from the pool. SPARE and POOL should not both be present; if both are absent the default action is determined by the restore-time macros mentioned above.
   
   TOTAL indicates that the entire on-line filestore is to be dumped
   
   
2. DUMP TAPES or
   DUMP TAPES,number or
   DUMP TAPES,ALL
   
   where number is the number of non-TAPEWRONGed spare tapes for which details are to be listed, and ALL indicates all such tapes. If neither number nor ALL appears, up to 10 such tapes will be listed.
   
   
3. DUMP disposal or
   DUMP disposal,number or
   DUMP disposal,ALL
   
   where disposal is REUSE if the tapes are to be released for re-use, that is to become spare, or RETURN if the tapes are to be returned to the pool.
   
   number is the number of tapes to the released or returned.

Forbidden contexts

NOT OPERATOR, REMOTE

Execution

Format 1 can be used to override the installation parameter DUMPTIME which determines when the incremental dumper is to be initiated. Usually it causes a dump to ne initiated immediately, but if a dump is already in progress when DUMP is issued, the command is validated (for example, to check that any tsns are usable); the command is then stored and will determine the tape selection for the next increment in the dump if one is necessary. Note that only one DUMP command can be stored; if two are issued successively whilst an increment is being written, the second overrides the first. Any stored command will be lost if a GEORGE break occurs.

The TOTAL parameter should be used with caution, since the resulting dump will take a very long time unless the filestore is small.

Format 2 causes the following to be listed on the console.

1. The tsns of the current dump tapes, if any. These are the tapes used or in use for the last increment in :SYSTEM.INCINDEX, unless this increment was prematurely terminated, or is still in the process of being set up. The current tapes will be used for the next increment unless overridden by tsn, SPARE or POOL parameters to the DUMP command, or unless the NEW parameter has been used with whichever of the restore-time macros DTFILEINC, DTRESTINC or DTAFTERREST applies.
   
   
2. The tsns of spare tapes in the order in which they will be used by Dumper. This list will include TAPEWRONGed tapes, even though they cannot be used, but the number of non-TAPEWRONGed tapes listed is regulated as described under Format above. TAPEWRONGed tapes are indicated by (O), (U) or (O,U) after the tsn, depending on whether they are operator or user TAPEWRONGed, or both
   
   
3. Parameters supplied to any stored DUMP command.

The output from DUMP TAPES thus enables the operator to establish the state of the dumping system and in particular to locate tapes which will be used for the next increment.

For format 3, obsolete dump tapes as specified, or obsolete tapes up to the specified number, if they exist, are made spare for re-use or returned to the pool. The following messages are sent to the operator's console

    MTS list of tsns TO-BE-REUSED - INCREMENTS OBSOLETE
    MTS list of tsns RETURNED - INCREMENTS OBSOLETE

If all the tapes for an increment have been released, that increment must have been obsolete and so its record in INCINDEX is deleted. If this happens, the following message is output

    RECORD(S) DELETED FOR INCREMENT(S) list of increments

Note: The releasing of dump tapes is performed automatically by TTTP and so it should not generally be necessary to use format 3. Indeed use of it bypasses the security built into TTTP against tapes being overwritten

Examples

Error Messages

z NOT RECOGNISED
MT tsn IS NOT AVAILABLE FOR USE BY DUMPER
INVALID COMBINATION OF PARAMETERS
PARAMETER NULL
NEGATIVE NUMBER NOT ALLOWED

CANCEL DUMP

Function

1. Causes preparations for an increment to be abandoned
2. Cancels a stored DUMP command

Format

CANCEL DUMP

Forbidden contexts

NOT OPERATOR, REMOTE

Execution

If Dumper is in the process of setting up an increment and has not output the START OF INCREMENT message, the preparations will be abandoned. An increment can only be cancelled whilst Dumper is selecting and positioning tapes. The following response will appear on the operator's console.

    INCREMENT n ABANDONED AND OBLITERATED

If there is a stored DUMP command, it will be forgotten.

An error is given if there is no dump in progress.

Notes

The following points should be noted about the action of CANCEL DUMP

1. Any outstanding tape requests for an abandoned increment will remain in the system
   
   
2. If tapes are obtained from the pool for an increment which is then cancelled they will be left as spare :DUMPER.GEO3DUMPTAPEs
   
   
3. Dumper will not immediately implement a CANCEL DUMP command while it is waiting for either of the following requests to be granted
   
       PLEASE ISSUE DUMP COMMAND
       PLEASE LOAD POOLTAPE
   
   In the first case, and normally in the second case, refusal of the request effectively cancels the dump, so action on CANCEL DUMP is then unnecessary. If either request is granted, the waiting CANCEL DUMP command then causes the dump to be cancelled

Error Message

NO CANCELLABLE DUMP