IBM z13s Technical Manual page 153

Before you activate an LPAR, main storage (and optionally, expanded storage) must be
defined to the LPAR. All installed storage can be configured as main storage. Each z/OS
individual LPAR can be defined with a maximum of 4 TB of main storage. z/VM supports 1 TB
of main storage.
Main storage can be dynamically assigned to expanded storage and back to main storage as
needed without a POR. For more information, see "LPAR single storage pool" on page 116.
Memory
storage resources for z/Architecture LPARs that run operating systems that support dynamic
storage reconfiguration (DSR). This process is supported by z/OS, and z/VM V5R4 and later
releases. z/VM, in turn, virtualizes this support to its guests. For more information, see 3.7.5,
"LPAR dynamic storage reconfiguration" on page 129.
Operating systems that run as guests of z/VM can use the z/VM capability of implementing
virtual memory to guest virtual machines. The z/VM dedicated real storage can be shared
between guest operating systems.
Table 3-6 shows the z13 storage allocation and usage possibilities, depending on the image
mode.
Table 3-6 Main storage definition and usage possibilities
Image mode Architecture mode
(addressability)
ESA/390 z/Architecture (64-bit)
ESA/390 (31-bit)
ESA/390 TPF ESA/390 (31-bit)
Coupling facility CFCC (64-bit)
Linux only z/Architecture (64-bit)
ESA/390 (31-bit)
b
z/VM z/Architecture (64-bit)
zACI z/Architecture (64-bit)
a. z/VM supports the use of expanded storage, but expanded storage is not recommended for z/VM V6.3.
b. z/VM mode is supported by z/VM V6R2 and later.
Note: When an I/O drawer (carry forward only) is installed, the maximum amount of LPAR
memory is limited to 1 TB.
ESA/390 mode
In ESA/390 mode, storage addressing can be 31 or 64 bits, depending on the operating
system architecture and the operating system configuration.
An ESA/390 mode image is always initiated in 31-bit addressing mode. During its
initialization, a z/Architecture operating system can change it to 64-bit addressing mode and
operate in the z/Architecture mode.
cannot
be shared between system images. It is possible to reallocate dynamically
Maximum main storage
Architecture
16 EB
2 GB
2 GB
1.5 TB
16 EB
2 GB
16 EB
16 EB
z13s
definition
4 TB
128 GB
2 GB
1 TB
1 TB
2 GB
1 TB
1 TB
Chapter 3. Central processor complex system design
Expanded storage
s
z13 Operating
definable system usage
Yes Yes
Yes Yes
Yes No
No No
Only by z/VM
Yes
Only by z/VM
Yes
Yes Yes
Yes No
a
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