IBM DS8700, Введение и руководство по планированию

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Frame configuration notes
There are two types of frame configurations supported, which are commonly
designated as A and B frames. An A frame is the base configuration (Mode 951)
and contains not just power and storage but also the I/O enclosures, Ethernet
switch, Hardware Management Console (HMC), and I/O bays. If more storage is
needed than the A frame (base Model 951) can provide, the next step is to add a B
frame, or expansion (Model 95E). The 95E contains more storage and more I/O
bays, increasing the number of device adapter cards you can select. Up to three
expansion models can be added to the configuration.
Note:
The design of this enclosure assumes that all drives used are homogeneous,
possessing the same interface speed, type - all native serial-attached SCSI
(SAS), all Nearline-SAS (NL), or all solid state drives (SSDs) and capacity.
However, drives with differing speeds can be combined if the capacity is the
same. An exception to this is that intermixing encrypting and
non-encrypting drives is not supported.
DS8800 (Business Class Cabling feature)
The IBM System Storage DS8800 business class cabling feature offers a streamlined,
lower cost configuration than the standard configuration. The DS8800 business
class cabling feature reconfigures the Model 951, reducing the number of installed
device adapters and I/O enclosures while increasing the number of storage
enclosures attached to the remaining device adapters. The business class option
allows a system to be configured with more drives per device adapter, reducing
configuration cost and increasing adapter usage.
The DS8800 Model 951 with business class cabling has the following features:
v Cost-optimized cabling
v
Dual two-way processor complex
v Up to 128 GB of processor memory on a two-way configuration
Note: A 16 GB processor memory option is available with feature code 4211 for
the two-way configuration, business class cabling feature.
v
Up to 4 host adapters or up to 32 host ports, FCP (Fibre Channel protocol) or
FICON
The DS8800 Model 951 Business Class Cabling feature supports up to 240 disk
drives. For more information, including maximum storage capacities, see
“Overview of physical configurations” on page 89 The cabling of the expansion
frame remains the same for both the standard and business class.
Note: The DS8800 high-density business class disk drive cable option is an
optional feature (feature code 1250). Up to 240 drives are supported on a
two-way, with single-phase power optional.
DS8000 model conversion limitations
Model conversions are not supported on the DS8800. There are several limitations
for the DS8700, noted below.
If a third and fourth expansion unit are attached to a DS8700, the following
considerations need to be made:
v
If the primary in a Global Mirror relationship has a third and fourth expansion
frame, then FlashCopy pairs are limited to 1,000
Chapter 1. Introduction to IBM System Storage DS8000 series
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