z/VM: CP Commands and Utilities Reference - z/VM - IBM

SET SCMEASURE
Responses
device should be disabled for collecting subchannel measurements when it is
initialized, CP does not prevent you from turning subchannel measuring on for
that device after it is initialized.
5. The SET SCMEASURE command will assign an SCMBK to a device or return
an assigned SCMBK to the available pool to be reused. To obtain information
on the number of SCMBKs on your system, use the QUERY SCMBKS
command (page 982).
Format-0 measurement blocks:
1. During initialization, CP allocates 1 SCMBK for every subchannel on the system
and rounds the amount of storage up to the nearest page boundary. Thus, you
have enough SCMBK space for every real device on your system plus some
free SCMBK space. How much free SCMBK space you have will vary,
depending upon how many real devices you have on your system.
2. You should plan for additional SCMBK space if you intend to dynamically add
new real devices to your running system. At initialization, you can allocate more
free SCMBK space than CP would normally allocate using the SCMBK operand
of the STORAGE statement in the system configuration file. For more
information, see the z/VM: CP Planning and Administration book.
3. If you run out of free SCMBK space on a running system and you need to
measure additional real devices, you have two choices:
a. Re-IPL and specify more free SCMBK space using the SCMBK operand
mentioned in Usage Note 2, or
b. Stop collecting subchannel measurement data for one or more devices.
When you use one of the following commands:
v DELETE DEVICE (page 223)
v DELETE IODEVICE (page 223)
v DELETE RDEVICE (page 228)
v SET SCMEASURE OFF (page 1377)
CP returns the SCMBK assigned to that device (or devices) to the pool of
available SCMBKs. It is then available to be used to collect subchannel
measurement data for another device.
Response 1:
To tell CP to begin collecting subchannel measurement data for devices 127
through 130, enter the following SET SCMEASURE command:
set scmeasure on 127-130
Subchannel measuring for device 0127 is on
Subchannel measuring for device 0128 is on
Subchannel measuring for device 0129 is already on
Subchannel measuring for device 012A is already on
Subchannel measuring for device 012B is on
Subchannel measuring for device 012C is on
Subchannel measuring for device 012D is on
Subchannel measuring for device 012E is already on
Subchannel measuring for device 012F is already on
Subchannel measuring for device 0130 is on
Ready;
Note that CP was already collecting subchannel measurement data for devices 129,
12A, 12E, and 12F.
Response 2:
1378 z/VM: CP Commands and Utilities Reference