6947ch08.fm Draft Document for Review April 7, 2004 6:15 pm
192 IBM eServer zSeries 990 Technical Guide
Figure 8-2 CUoD for memory example
This one-book z990 model has two 16 GB memory cards, resulting in 32 GB of installed
memory in total. Therefore, a concurrent memory upgrade within this model A08 can be done
up to the 32 GB limit, via LIC-CC, but a memory upgrade to 40 GB would require the book’s
memory cards replacement by two 32 GB memory cards and is disruptive.
However, as shown in the example, the upgrade of this model A08 with 24 GB of memory to a
model B16 with 40 GB is concurrent, as the additional book comes with 2 memory cards (in
this case, two 8 GB memory cards). The additional 16 GB memory capacity is enabled by
LIC-CC on the second book (Book 1).
In the last part of this example, this model B16 server is concurrently upgraded to 48 GB, by
LIC-CC enabling all the installed memory.
For a logical partition’s memory upgrade, reserved storage must have been previously
defined to that logical partition. It makes use of the LPAR Dynamic Storage Reconfiguration
(DSR) function. DSR allows a z/OS or OS/390 operating system running in a partition to add
its reserved storage to its configuration, if any unused storage exists. When the operating
system running in a partition requests an assignment of a storage increment to its
configuration, PR/SM checks for any free storage and brings it online dynamically.
Concurrent memory upgrades also require that:
򐂰Memory must not be running in degraded mode.
Upgrades are disruptive until failing memory cards have been replaced.
2 Memory Cards
(16 GB each)
32 GB
Max
24 GB
2084-A08 24 GB
2 Memory Cards
(16 GB each)
32 GB
Max
24 GB
2084-B16 40 GB
2 Memory Cards
(8 GB each)
Book 0
Book 0
Book 1
2 Memory Cards
(16 GB each)
2084-B16 48 GB
2 Memory Cards
(8 GB each)
16 GB (Max)
Book 0
Book 1
CUoD
+ 16 GB
+ Model upgrade
CUoD
+ 8 GB
16 GB (Max)
32 GB (Max)