Replacement capacity offerings

With the replacement capacity offerings, such as CBU and CPE, you need to be cautious when you try to apply a permanent upgrade primarily because with these offerings, active temporary capacity is not replaced by permanent capacity. Replacement capacity offerings add engines and capacity levels to the permanent engine and capacity levels. Therefore, when a permanent upgrade changes the engine counts or capacity levels, there is a corresponding change in the active temporary records. Replacement capacity that was activated before a permanent upgrade will be active on top of the new permanent configuration.

There are four basic scenarios to consider when planning for a permanent upgrade with a replacement capacity offering active. These scenarios include:

• Are there sufficient PUs on the system to allow for the permanent upgrade?
• Will the resultant configuration (permanent plus any active temporary records) after applying the permanent upgrade be a valid configuration?
• If you are on a subcapacity system and have replacement capacity records active, will the permanent upgrade result in an engine configuration that goes into the second drawer on a multi-drawer system?
• Do you have sufficient CBU features to continue activation at the new processor level?

Scenario 1: Are there sufficient PUs available on the system?

Because replacement capacity engines are not converted into permanent engines when a permanent upgrade is applied, you must ensure that there are sufficient engines available to activate the permanent upgrade.

Suppose you are running an IBM® z16 Max39 (ie. 39 available PUs) at model capacity 735 with CBU engines active to a 739 level. (See Figure 1.) With this scenario, you cannot perform any permanent engine upgrades, regardless of engine type, until the appropriate number of CBU engines have been deactivated.

Scenario 2: Will the resultant configuration be a valid configuration?

A subcapacity system has four subcapacity levels. When you activate a temporary upgrade, you activate one or more additional engines and one or more additional capacity levels. If you then apply a permanent upgrade, the resulting configuration must allow for the same number of temporary capacity levels and engines level to be active.

Suppose you are running an IBM z16 at model capacity 635 with CBU engines active to a 739 level (adding one capacity level and four engines). You then try to apply a permanent upgrade to a 735. The system would then attempt to add four engines and go up one capacity level from the new permanent configuration. Because there are no capacity levels beyond 7xx, the upgrade would fail. (See Figure 3.)

In this case, for the upgrade to work, first lower the CBU activation to a 639, and then apply the upgrade.

Scenario 3: Will resultant configuration go into the second drawer?

If you are on a subcapacity system, with a temporary record active, any permanent upgrade that moves the CP capacity marker to the second drawer will fail. This failure will occur even if the resulting capacity appears to be valid.

Suppose you are running an IBM z16 at model capacity 635 with CBU engines active to a 738 level. (See Figure 4.) Then, if you try to apply a permanent upgrade to a 637, your upgrade will fail because you are moving the capacity marker beyond the 739 level into the second drawer. (See Figure 5.)

For this upgrade to work, first decrease the CBU activation to a 637, and then apply the permanent upgrade. You could then activate additional CBU processors if necessary.

Scenario 4: Using CBU is there sufficient CP features codes for increasing engine speed?

With CBU, CP capacity is managed by features codes. You select feature codes to either add engines or increase the engine speed.

Suppose you are running at capacity level 611 with increase capacity to a 711 using CBU. This requires 11 CP feature codes. Then, while CBU is active, you attempt to activate a permanent upgrade that adds an additional processor to go to a 612. The upgrade will fail because 12 CBU CP feature codes are now required.

To prevent this failure, either deactivate CBU prior to installing the permanent upgrade, or replenish the CBU record to add an additional CBU CP feature code prior to installing the permanent upgrade.