Summary Of Capacity On-Demand Offerings - IBM z13s Technical Manual

planning is done in advance. Planning ahead is a key factor for enabling nondisruptive
upgrades.
The following list describes the major reasons for disruptive upgrades. However, by carefully
planning, and by reviewing "Suggestions to avoid disruptive upgrades", you can minimize the
need for these outages:
When reserved storage was not previously defined, LPAR memory upgrades are
disruptive to image upgrades. IBM z/OS and z/VM support this function.
Installation of an extra CPC drawer to upgrade a Model N10 to a Model N20 (one or two
drawers) is non-concurrent.
When the OS cannot use the dynamic I/O configuration function, an I/O upgrade is
disruptive to that LPAR. Linux, IBM z/Virtual Storage Extended (z/VSE), Transaction
Processing Facility (TPF), IBM z/Transaction Processing Facility (z/TPF), and CFCC do
not support the dynamic I/O configuration.
Suggestions to avoid disruptive upgrades
Based on the previous list of reasons for disruptive upgrades ("Planning for nondisruptive
upgrades" on page 352), here are several suggestions for avoiding or at least minimizing
these situations, increasing the potential for nondisruptive upgrades:
Using an SE function under Operational Customization tasks called
add
, CPs and zIIPs can be added concurrently to a running partition. The initial or
reserved number of processors can be dynamically changed.
The OS that runs in the targeted LPAR must support the dynamic addition of resources,
and be able to configure processors online. The total number of defined and reserved CPs
cannot exceed the number of CPs supported by the OS. IBM z/OSV1R11, z/OS V1R12,
and z/OS V1R13 with program temporary fixes (PTFs) supports up to 100 processors.
IBM z/OS V2R1 also supports up to 141-way in non-SMT mode and up to 128-way in SMT
mode. IBM z/VM supports up to 64 processors.
Configure reserved storage to LPARs. Configuring reserved storage for all LPARs
their activation enables them to be non-disruptively upgraded. The OS running in the
LPAR must be able to configure memory online. The amount of reserved storage can be
higher than the CPC drawer threshold limit, even if the second CPC drawer is not installed.
The current partition storage limit is 4 terabytes (TB). IBM z/OS and z/VM support this
function.
Consider the plan-ahead memory options. Use a convenient entry point for memory
capacity, and consider the memory options to enable future upgrades within the memory
cards that are already installed on the CPC drawers. For details about the offerings, see
2.4.3, "Memory configurations" on page 56.
Considerations when installing an additional CEC drawer
During an upgrade, an additional CEC drawer can be installed non-concurrently. Depending
on your I/O configuration, a fanout rebalancing might be desirable for availability reasons.

8.9 Summary of capacity on-demand offerings

The CoD infrastructure and its offerings are major features for z13s servers. The introduction
of these features was based on numerous customer requirements for more flexibility,
granularity, and better business control over the z Systems infrastructure, operationally and
financially.
Logical Processor
Chapter 8. System upgrades
before
353