Specifications

82 IBM System z Personal Development Tool: Volume 3 Additional Topics
No DASD is defined for the instances in this example; the instances will share the DASD
defined for the group controller.
Note that all sharing instances use the same addresses (device numbers) for the shared
devices. There is no provision to have different addresses (for different instances) for the
same shared device.
If a zPDT instance operates under the group controller, then any OSA devices might be
shared devices, managed by the group controller, or each instance may have a private OSA.
5
If the OSA is used in OSE (non-QDIO mode) then the OAT definitions must be customized
with the names of the instance members (specified as “MEMBER names”) and the IP
address(es) for each instance.
Standard operating rules still apply, of course. We cannot IPL the same z/OS system into two
instances at the same time.
6
In our small example, we have two z/OS systems (the second
one is on the SARES1 volume provided with the AD-CD package). In the absence of shared
ENQ functions
7
, you must manage any active data set sharing. The 1090 correctly emulates
disk RESERVE and RELEASE functions and these protect VTOC and catalog updates in the
normal z/OS manner.
Startup for our controller and two instances, working from the Linux desktop, might go as
follows:
(login as root; open a terminal window)
# xhost + allow multiple users to start x3270
# su ibmgroup work as group controller
$ cd /home/ibmgroup
$ awsstart group1 start group controller
(startup messages)
(open another terminal window)
# su ibmsys1
$ cd /home/ibmsys1
$ awsstart aprof1 working as ibmsys1
(startup messages) ibmsys1 instance
$ x3270 -port 3270 mstcon@localhost & working as ibmsys1
$ x3270 -port 3270 tso@localhost & working as ibmsys1
$ ipl a80 parm 0a8200 working as ibmsys1, IPL z/OS
(open another terminal window)
# su ibmsys2
$ cd /home/ibmsys2
$ awsstart profSB working as ibmsys2
(startup messages) ibmsys2 instance
$ x3270 -port 3271 mstcon@localhost & working as ibmsys2
$ x3270 -port 3271 tso@localhost & working as ibmsys2
$ ipl a90 parm 0a90sa working as ibmsys2, IPL z/OS
In this example, we used a different terminal window to start the group controller and each
z/OS instance. This allows us to send commands (such as awsstop) to the appropriate
application later.
4
An example using a single 3270 port number is given later in the text.
5
zPDT releases prior to 39.16 could not have multiple OSA tunnel devices; this limitation was removed with release
39.16 and later releases.
6
This statement ignores situations where the use of different PARMLIB members allows the same z/OS to be IPLed
in multiple LPARs or instances. This involves separate paging, spooling, and various VSAM data sets for each
LPAR/instance. The z/OS AD system used for many of our examples is not set up for this type of usage.
7
Sharing ENQ/DEQ functions is typically done the GRS functions of a sysplex configuration. We do not have a
sysplex here and there are no global ENQ/DEQ controls.