Chapter 4. Operating The Storage Subsystem - IBM DS4800 Installation, User And Maintenance Manual

Chapter 4. Operating the storage subsystem

To ensure optimal operation of your system, always follow these best practices
guidelines:
v Ensure that your system is in an optimal state before you shut it down. Never
v Back up the data on your storage drives periodically.
v To maintain power redundancy, plug the storage subsystem's right and left RAID
v Before any planned system shutdown or after any system additions, removals, or
v During any maintenance or attended power-up procedure, carefully follow the
v The storage subsystem supports simultaneous power-up to the system
v A storage system in an optimal state should recover automatically from an
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turn the power off if any Needs Attention LED is lit; be sure to resolve any error
conditions before you shut down the system.
controller units into two independent external power circuits through ac
distribution units inside a rack cabinet or directly into external receptacles.
Similarly, the right and left power supplies of the DS4000 storage expansion
enclosures attached to the DS4800 should be plugged into the same two
independent external power circuits as the DS4800. This ensures that the
DS4800 and all its attached storage expansion enclosures will have power if only
one power circuit is available. In addition, having all the right or all the left power
cables plug into the same power circuit will enable the components in the storage
subsystem to power on simultaneously during an unattended restoration of
power. See Figure 71 on page 99 for an example of redundant power
connections.
Note: Do not overload the circuits that power your storage subsystem and
storage expansion enclosures. Use additional pairs of power distribution
units (PDUs) if necessary. Refer to the Installation, User's, and
Maintenance Guide for your storage expansion enclosures for information
on power requirements. Contact your IBM service representative for
additional information if needed.
modifications (including firmware updates, logical drive creations, storage
partitioning definitions, hardware changes, and so on), save the storage
subsystem profile as explained in the DS4000 Storage Manager guide for your
operating system. Save the profile in a location other than the logical drives
created for the DS4800.
power-up sequence listed in "Turning on the storage subsystem" on page 105.
You should check that each component of the subsystem is powered-on in the
proper order during this entire power-up procedure to ensure that the controller
will optimally access all of your storage subsystems.
components; however, you should always follow the power-up sequence listed in
"Turning on the storage subsystem" on page 105 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.
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