Storage Server Components - IBM DS4800 User, Installation And Maintenance Manual

v The storage subsystem supports simultaneous power-up to the system
v A storage system in an optimal state should recover automatically from an

Storage server components

The DS4800 directs and manages the I/O activity between a host and the drives in
a RAID array. The storage subsystem has eight single-ported host channels (4 per
controller) and can support up to 256 hosts with two FC connections to the DS4800
(one to controller A and one to controller B for redundancy). The storage subsystem
has four dual-ported drive channels and can support up to 224 Fibre Channel or
SATA drives with a maximum of 2048 addressable logical drives.
Note: The DS4800 model 80A/H subsystem support the attachment of up to 112
The DS4800 has Intel
or 8 GB of cache random access memory (RAM) (depending on the DS4800
model). Its host-side and drive-side fibre channel port can support fibre channel
speeds of up to 4 Gb/s. Figure 1 on page 8 shows the DS4800 with front bezel in
place.
components; however, you should always follow the power-up sequence listed in
"Turning on the storage subsystem" on page 97 during any attended power-up
procedure.
unexpected shutdown and unattended simultaneous restoration of power to
system components. After power is restored, call IBM support if any of the
following conditions occur:
– The storage subsystem logical drives and arrays are not displayed in the
DS4000 Storage Manager graphical user interface (GUI).
– The storage subsystem logical drives and arrays do not come online.
– The storage subsystem logical drives and arrays seem to be degraded.
drives only as standard. An additional entitlement must be purchased to
allow the attachment of up to 224 drives to the DS4800 model 80A/H
subsystem.
®
Pentium
®
processors and RAID controllers with either 2, 4
7
Chapter 1. Introduction