Testing Your System for Automated Dynamic I/O
After
you’ve implemented your RESET and image profile changes, you can test your
system to make sure it’s ready for Dynamic I/O. To perform the test, issue the
“D IOS,CONFIG(ALL)” command. If your system is ready for
Dynamic I/O, you’ll see non-zero values for the entries in the “Hardware System
Area Available for Configuration Changes” section. These entries show the
number of devices, control units, and channel paths that you can add to your
system.
Performing the Automated Dynamic I/O Process
Performing
an Automated Dynamic I/O involves these steps:
1.
Create a new IOCDS, using HCD, to define the new device(s) to the hardware.
2.
Create a new IODF file, using HCD, to define the device to MVS.
3.
Activate the software portion of the configuration, using the ACTIVATE SOFT
command, on all but one LPAR.
4.
Activate the hardware portion of the configuration, using the ACTIVATE command,
on one LPAR.
5.
Point the RESET profile to the new IOCDS, using the ACTIVATE ACTIOCDS command.
The
first two steps are common systems programmer functions. The only requirement
for Dynamic I/O in these steps is to define the devices as Dynamic.
Activate the Software Portion of the Configuration
After
you’ve created the IOCDS and IODF files, you’re ready to activate the software
(MVS) portion of the new configuration. The software portion is the definition
of the device UCBs used by MVS to communicate with each device. The software
portion should be implemented on all but one LPAR. #Before activating the
software portion, you should execute these three commands to check your new
configuration:
D
IOS,CONFIG(ALL): Issue this command to display the current token. After the
activations, you can verify the token was modified.
ACTIVATE
IODF=xx,TEST: Issue this command to test the hardware and software portions
before making any changes. Replace xx with your new IODF suffix. The output of
this command will identify potential errors and also will display the devices
added or deleted when the activate occurs.
ACTIVATE
IODF=xx,SOFT,TEST: This final command will test the software portion of the
activate. The output of this command informs you that the activate will cause a
mismatch between the hardware and software configurations.
This is expected, since the hardware portion of the configuration hasn’t been
activated. Note: Replace xx with your new IODF suffix.
Once
you’re comfortable with the results of the aforementioned commands, issue the
following command to activate the software portion of the configuration on all
but one LPAR on the machine. Note: Replace xx with your new IODF suffix:
ACTIVATE
IODF=xx,SOFT
If you display the device (i.e., D U,,,0550,1),
you’ll see that MVS has a UCB for the device. But, if you display the path for
the device (DS P,0550,1), you’ll see there’s no path associated with this
device. This is because the hardware portion of the configuration hasn’t yet
been activate d . If you issue the D IOS,CONFIG(ALL) command, you’ll
see that the name of the active IODF data set has changed, but the IODF name in
the token still points to the old IODF name.
Activate the Hardware Portion of the Configuration
After
you activate the software portion of the configuration on all but one LPAR,
you’re ready to implement the hardware portion of the configuration. When you
activate the hardware portion, this will affect every LPAR on the machine. On
the remaining LPAR, you’ll activate both the software and the hardware
portions, using this command (replace xx with the suffix of your new IODF):
ACTIVATE
IODF=xx
You should verify the activation by
displaying the new devices using both the D U and DS P commands. You also
should issue the D IOS,CONFIG(ALL) command to verify that the IODF name in the
token was changed to the new IODF name. Point the RESET Profile to the New
IOCDS
The
final step in the Automated Dynamic I/O process is to point your RESET profile
to the new IOCDS. Use this command (replace Ax with the appropriate IOCDS
slot):
ACTIVATE
ACTIOCDS=Ax
The
ACTIVATE ACTIOCDS command doesn’t perform any dynamic I/O functions. It only
changes the active IOCDS pointer. Since you previously changed your RESET
profile to “Use Active IOCDS,” the next time you POR, you’ll be using the
proper IOCDS. After you issue the ACTIVATE ACTIOCDS command, you should go into
your HMC and verify that the Active IOCDS pointer was modified as expected.
Conclusion
We’ve
covered several variations of the Dynamic I/O ACTIVATE command. If you prefer
to use panels rather than the native ACTIVATE commands, the HCD provides panels
you can use to perform your hardware and software activates. For more
information on Dynamic I/O, see the IBM publication Hardware Configuration
Definition Planning (GA22-7525). This manual contains a wealth of information
and also documents recovery steps to take if your activates don’t go as
planned.
