TOPS-20 Commands Reference Manual
DISMOUNT
Gives up access to the specified structure or tape set.
Format
@DISMOUNT medium (NAME) dev: /switch(es)
where:
| medium | is one of the following optional arguments:
| ||||
| dev: | is either the structure identification (or alias), or a logical name referring to the tape set (the tape setname specified in your previous MOUNT command), or a logical device name of the form MTn:. The colon after the device name is optional. | ||||
| /switches | are keywords, chosen from the list below, indicating your choice of DISMOUNT command options. |
DISMOUNT Command Switches
(for use with argument STRUCTURE
only)
| /NOWAIT | tells the system to return your terminal to TOPS-20 command level as soon as you give the DISMOUNT command, and to send a message to your terminal when the request has been processed. Otherwise, your terminal waits for the message. |
| /REMARK:"remark" | sends the specified remark (of 119 or fewer characters, which must be enclosed in quotation marks [" "]) to the operator when he is notified of your request. The remark is sent only if you also include the /REMOVE switch. |
| /REMOVE | tells the operator that you want him to physically dismount the structure from the drive; makes the structure unavailable for further mount requests. See also Hints - Action of DISMOUNT Command Including /REMOVE Switch, below. |
| /STRUCTURE-ID:structure identification | gives the name of the structure as recorded in the disk(s); used when you give some alias as argument dev:, above. See Hints - Using the /STRUCTURE-ID Switch, below. |
Characteristics
Action of DISMOUNT STRUCTURE Command
Ordinary DISMOUNT STRUCTURE
The DISMOUNT STRUCTURE command reduces by 1 the mount count of the specified structure (the number of users who have given a MOUNT but not a DISMOUNT command for the structure) if you had given a previous MOUNT command for it. An ordinary DISMOUNT STRUCTURE command does not withdraw the structure from system use.
Including /REMOVE Switch
If you include the /REMOVE switch when giving the DISMOUNT STRUCTURE command, the specified structure is made unavailable for further mount requests. The operator is informed of your dismount request, and any further action depends on him. If he denies your request, the structure is again made available to other users; if he grants your request, the structure remains unavailable for further mount requests, and is taken off line and physically removed. Under extreme conditions the operator may take a structure off line and physically remove it even though some users have not dismounted the structure. Before doing so, he will usually send a message to such users to allow them to close their files.
Action of DISMOUNT TAPE Command
The DISMOUNT TAPE command unloads the currently mounted volume of the specified tape set (i.e., rewinds it completely onto its source reel) so that it can be physically removed by the operator, and returns the tape drive to the pool of available resources. (Note that if the /NOUNLOAD switch was given in your original MOUNT command, no volumes are unloaded by the system or removed by the operator, even after your DISMOUNT command is completed.) If a logical name (such as the setname of the tape set) is used in the DISMOUNT command to specify the tape set, the system also withdraws the definition of the logical name. Use DISMOUNT TAPE only for tape drives having device names of the form MTn:; drives obtained using the MOUNT command. Use UNLOAD to unload tapes from drives having device names of the form MTAn:.
Hints
Omitting "medium" Argument
If the dev: argument of your DISMOUNT command will be unambiguous (for example, you do not have both a structure and a tape set mounted using the same device name), you need not specify the medium. The shortened command, DISMOUNT dev:/switch(es), is sufficient.
Using the /STRUCTURE-ID Switch
The /STRUCTURE-ID switch gives the name of the structure as recorded in the disk(s) of the pack itself, where it is used by the system for identification. You may use this switch to dismount a structure that had been mounted using an alias different from its structure identification. (See Hints - Using the /STRUCTURE-ID Switch, in the MOUNT command description.)
Using INFORMATION VOLUMES before DISMOUNT TAPE
If you give the INFORMATION VOLUMES command before dismounting a tape set, the system will respond with a list of the volids for mounted volumes, including volids for any volumes newly added to the set. You should keep an up-to-date record of these for use with further MOUNT commands.
Effect on Terminal
The DISMOUNT command with the /NOWAIT switch, leaves your terminal at TOPS-20 command level. If you have not given the /NOWAIT switch, your terminal waits until the system has processed your request, or until you give a CTRL/C to return to TOPS-20 command level. This CTRL/C does not cancel your request.
Related Commands
| CANCEL | for withdrawing mount requests before they are processed |
| INFORMATION AVAILABLE DEVICES | for finding which tape devices (if any) have been assigned to your job |
| INFORMATION MOUNT-REQUESTS | for finding out information about pending mount requests for structures and tape sets, and currently mounted tape sets |
| INFORMATION STRUCTURE | for finding out information about the specified mounted structure, including its mount count and the names of users who have given the MOUNT, CONNECT, and ACCESS commands for the structure |
| INFORMATION VOLUMES | for finding out the volids of all mounted volumes (including newly created volumes) of a tape set |
Examples
- Dismount a magnetic tape set you have been using.
@DISMOUNT TAPE MT3: [Tape dismounted]
- Dismount the same tape set, referring to it by its setname.
@DISMOUNT TAPE LAT: [Tape dismounted, logical name LAT: deleted]
- Find out the volids of your tape set before dismounting it, in case the
tape set has been extended to another volume.
@INFORMATION VOLUMES MT3: Volumes of tape set LAT: LAT,00J16 @DISMOUNT MT3 [Tape dismounted]
- Find out if you have any mount requests pending or any currently
mounted tape sets. Dismount a currently mounted tape set (these display
the actual device name (here, MTA0) in the column headed, Status).
@INFORMATION MOUNT-REQUEST/USER Tape/Disk Mount Queue: Volume Status Type Write Req Name Req# Job# User ------- ------- ---- ------- -------- ---- ---- ------ UNLBLD MTA0 Tape Locked UNLBLD 128 55 LATTA There is 1 Request in the Queue @DISMOUNT TAPE UNLBLD: [Tape dismounted, logical name UNLBLD: deleted]
- Dismount a structure you have mounted named SNARK.
@DISMOUNT SNARK Structure SNARK: dismounted
- Find out whether your mount request for a structure has been satisfied
yet (it has not). Use the CANCEL command to withdraw this request.
@INFORMATION MOUNT-REQUESTS Tape/Disk Mount Queue: Volume Status Type Write Req Name Req# Job# User ------- ------- ---- ------- -------- ---- ---- ---------- MARK MTA1 Tape Enabled MARK 126 60 HOVSEPIAN TAPE MTA3 Tape Enabled TAPE 148 13 WALLACE LATB Waiting Disk LATB 157 65 LATTA There are 3 Requests in the Queue @CANCEL MOUNT 157 [1 mount request canceled]
- Find out whether you can safely dismount and remove a structure you
have mounted. Use the SEND command to ask another user to dismount the
structure; then enable your capabilities and give a DISMOUNT command that
will physically remove it.
@INFORMATION STRUCTURE LATB: Status of structure LATB: Mount count: 2, open file count: 0, units in structure: 1 Foreign Users who have MOUNTed LATB: LATTA, GBLAINE Users ACCESSing LATB: LATTA, GBLAINE No users CONNECTed to LATB: @SEND GBLAINE PLEASE DISMOUNT LATB: AS SOON AS CONVENIENT. - I MUST REMOVE THE STRUCTURE. THANKS. @INFORMATION STRUCTURE LATB: Status of structure LATB: Mount count: 1, open file count: 0, units in structure: 1 Foreign Users who have MOUNTed LATB: LATTA Users ACCESSing LATB: LATTA No users CONNECTed to LATB: @END-ACCESS LATB:<OPERATOR> @ENABLE $DISMOUNT STRUCTURE LATB: /REMOVE/REMARK:"PLEASE LEAVE LATB: - ON RP06 CABINET" [Mount Request LATB Queued, Request-ID 164] Structure LATB: removed $DISABLE @