IBM System Storage Subsystem DS5020 - Manual (Page 36)

Note: Do not overload the circuits that power your storage subsystem and
storage expansion enclosures. Use additional pairs of ac power
distribution units (PDUs) if necessary. Refer to for information about
storage subsystem power requirements. Contact your IBM service
representative for additional information if needed.
v Before any planned system shutdown or after any system additions, removals, or
modifications (including firmware updates, logical drive creations, storage
partitioning definitions, hardware changes, and so on), complete the following
tasks:
1. Save the storage subsystem profile
2. Save the storage subsystem configuration
Make sure that you save the files in a location other than in the logical drives that
were created for the storage subsystem.
For more information about how to complete these tasks, check the DS Storage
Manager online help or the Storage Manager guide for your operating system.
v During any maintenance or attended power-up procedure, carefully follow the
power-up sequence listed in “Powering on the storage subsystem” on page 95.
Check that each component of the subsystem is powered-on in the proper order
during this entire power-up procedure so the controller will be able to optimally
access all of your storage subsystems.
v The storage subsystem supports simultaneous power-up to the system
components, but always follow the power-up sequence listed in “Powering on the
storage subsystem” on page 95 during any attended power-up procedure.
v A storage system in an optimal state recovers automatically from an 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 subsystems are not displayed in the
DS Storage Manager graphical user interface (GUI).
– The storage subsystem logical drives and subsystems do not come online.
– The storage subsystem logical drives and subsystems seem to be degraded.
Storage subsystem components
The storage subsystem has the following removable components. These
components, called customer replaceable units (CRUs), are accessible from the
front or back of the storage subsystem.
v Up to sixteen 4 Gbps Fibre Channel or SATA Enhanced Disk Drive Modules
(E-DDMs)
v Two RAID controllers
v Two ac power supply and fan units
v Two battery units
v SFP modules
The hot-swap features enable you to remove and replace 4 Gbps Fibre Channel or
SATA E-DDMs, power supply and fan units, and controllers without turning off the
storage subsystem. You can maintain the availability of your system while a
hot-swap device is removed, installed, or replaced.
6 IBM System Storage DS5020 Storage Subsystem: Installation, User’s, and Maintenance Guide