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BB-PBQUC-BM_1990
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help/dismount.hlp
There are no other files named dismount.hlp in the archive.
DISMOUNT command
The DISMOUNT command 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:
STRUCTURE - for dismounting file
structures (disk packs)
TAPE - for dismounting magnetic
tapes
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
1. Dismount a magnetic tape set you have been using.
@DISMOUNT TAPE MT3:
[Tape dismounted]
2. Dismount the same tape set, referring to it by its setname.
@DISMOUNT TAPE LAT:
[Tape dismounted, logical name LAT: deleted]
3. 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]
4. 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]
5. Dismount a structure you have mounted named SNARK.
@DISMOUNT SNARK
Structure SNARK: dismounted
6. 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]
7. 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
@