Restrictions exist on issuing the MONITOR ENAELE command while
the VM/370 Monitor is collecting and recording data.
Every MONITOR ENABLE command yields a new mask. Thus, for
example, if PERFORM and USER classes are currently being
collected, and you enter MONITOR ENABLE INSTSI!, then PERFORM and USER classes are stopped and INSTSI! is started.
The DASTAP operand in the MONITOR ENABLE command must be
specified prior to the MONITOR START TAPE command. DASTAP may be disabled at any time by respecifying the MONITOR ENABLE
command with DASTAP absent from the class list.
The SYSPROF class cannot be activated unless both the DASTAP and SCHEDULE classes are also active.
If data collection is in progress when you issue a MONITOR ENABLE command and an error occurs in the command line during
processing, no change is made to the status.
Unrecognizable keywords, conflicting or operands
generate appropriately different error messages.
Due to the potential security exposure that exists with
collecting terminal input and output data, the RESPONSE class
of data collection does not occur unless the system programmer sets the TRACE(1) bit in the LOCAL COPY file to a 1 and
reassembles the CP module DMKMCC. If this is not done, the RESPONSE class is considered an invalid operand of the MONITOR ENABLE command.
r , I INTERVAL nnnnn ISECI nn IMINI L J specifies the time interval to be used for the three timer driven data collection classes: PERFORM, USER, and DASTAP. The value specified by nnnnn is the number of seconds or
minutes between data collections. If no interval is specified
'on the MONITOR INTERVAL command, an error message is
generated. If you give an interval but enter neither SEC nor MIN, the default is SEC. The maximum allowatle interval is 9
hours (540 minutes or 32,400 seconds). The minimum is 30 seconds.
If the MONITOR INTERVAL command is not issued, the default
interval is 60 seconds. The MONITOR INTERVAL command can be
issued at any time; however, if data collection is already in
progress, the new interval does not take effect until the
current interval has elapsed.
nn specifies how frequently the VM/370 Monitor is to sample
channel status, control unit status, and device status for
the DASTAP class. The nn parameter specifies only seconds,
has a minimum value of 1, a maximum value of 99, and a
default value of 2. The amount of time specified by nn
must be less than the amount of time specified by nnnnn.
The value of nn and the value of nnnnn work together in the
following way. The VM/370 Monitor accumulates channel
status, control unit status, and device status in a buffer.
The value of nn determines the frequency of accumulation;
the value of nnnnn determines how frequently the buffer is
114 IBM VM/370 System programmer's Guide

START r page of GC20-1807-7 As Updated April 1, 1981 by TNL GN25-0829
written to tape. When the buffer is written to tape, it is
written as a class 6 (DASTAP) record under monitor code 02. The MONITOR interval is reset to the default of 60 seconds
whenever any of the following occurs: • The user issues MONITOR STOP, automatically
or the monitor stops • The system stops the MONITOR because of an unrecoverable I/O error • The end of tape or spool record limit is reached
, [To userid] [ BUFFS n] I I r , I ITAPE raddr '1I0DE{BOO }' I I I 1600 I [ BUFFS n] I I I 6250 , I I L .J I ICPTRACE I L .J
starts VM/370 Monitor data collection to the spool file or
tape, or starts the CP internal trace table. If no optional
parameter is provided, SPOOL is the default. KONITOR START SPOOL starts the VM/370 Monitor data collection using a spool
file for storage. When data collection is stopped and the spool is closed, the
spool file is added to the chain of reader files destined for
the virtual reader of the virtual machine defined by "userid." Userid may be an asterisk (*) if the recipient virtual machine
is to be the one from which the START command is issued. If
the TO USERID option is omitted, the userid specified in the SYSMON macro is used (See the VK/37Q The TO USERID option overrides the SYSMON specification and stays in effect until the system is
reinitialized or a new command is issued.
The monitor spool file is closed by a MONITOR STOP or MONITOR CLOSE command, or when the record count limit is reached (as
specified in the SYSMON macro), or when a system restart or
system shutdown occurs.
The filename and filetype is generated internally with the
filetype identifying date and time of starting.
The class of spool file is specified in the SYSMON macro and
defaults to "M". If no classes of data collection have been
specified with an ENABLE command, then those specified with
the SYSMON macro are used.
The number of monitor buffers used are as specified in the SYSMON macro, or as requested with the BUFFS option of the START command. The BUFFS option overrides the SYSMON specification only for the duration of the data collection
session. Future monitoring sessions subsequently return to
-t he - SY SftON-- sp-ec-i-fi-ea-t-io-n---- -u--nl-e-ss- --- -aija i n - o-verr-id-den. I-f - the
number of buffers specified in the SYSKON macro has been
defaulted, then the defaults described in the MONITOR START TAPE command are adopted. Part 2. Control Program (CP) 115