Processor Memory; Subsystem Device Driver For Open-Systems; Balancing The I/O Load - IBM DS8800 Introduction And Planning Manual

The storage unit supports the following operating systems for System z and S/390
hosts:
v Linux
v Transaction Processing Facility (TPF)
v Virtual Storage Extended/Enterprise Storage Architecture (VSE/ESA)
v z/OS
v z/VM
v z/VSE
For the most current information on supported hosts, operating systems, adapters
and switches, go to the System Storage Interoperation Center (SSIC) website at
www.ibm.com/systems/support/storage/config/ssic.

Processor memory

The DS8000 offers the following processor memory offerings.
DS8700
DS8800
The nonvolatile storage (NVS) scales with the selected processor memory size,
which can also help optimize performance. The NVS is typically 1/32 of the
installed memory.
Note: The minimum NVS is 1 GB.
For more information, see "Overview of physical configurations" on page 89.

Subsystem device driver for open-systems

The IBM System Storage Multipath Subsystem Device Driver (SDD) supports
open-systems hosts.
The Subsystem Device Driver (SDD) is enclosed in the host server with the native
disk device driver for the storage unit. It uses redundant connections between the
host server and disk storage in the DS8000 series to provide enhanced performance
and data availability.

Balancing the I/O load

You can maximize the performance of an application by spreading the I/O load
across clusters, arrays, and device adapters in the storage unit.
34
Introduction and Planning Guide
®
®
The DS8700 Model 941 two-way configuraton offers up to 128 GB of
processor memory.
The DS8700 Model 941 four-way configuration offers up to 384 GB of
processor memory.
The DS8800 Model 951 two-way configuration offers up to 128 GB of
processor memory.
The DS8800 Model 951 four-way configuration offers up to 384 GB of
processor memory.
The business-class feature, Model 951 two-way configuration, offers 16 GB
of processor memory with feature code 4211.