HP Smart Array Controller technology, 4th edition

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You can also recombine a split-mirrored array with the ACU. When you recombine a split-mirrored array,
you lose access to all data on the second array.
The Smart Array Advanced Pack (SAAP) may be required to use the mirror splitting and recombining
functions. For support information regarding mirror splitting on specific controllers, see the controller
QuickSpecs.
NOTE:
You must split or re-mirror arrays when the server is offline and operating in the
standard configuration mode of ACU.
Online drive flash
The present generation Smart Array controllers support online drive flashing, which saves time when
updating disk drive firmware. Instead of taking the hard disk drive (HDD) offline before loading a new
firmware image, you can download an updated HDD firmware image to the Smart Array controller and
update all of the HDDs the next time you reboot the server.
Recovery ROM
HP Smart Array controllers store a redundant copy of the controller firmware image to protect against data
corruption. If the active firmware image becomes corrupt, Smart Array controllers use the redundant
firmware image and continue operating. The recovery ROM provides protection against power outages
during firmware flashing.
Pre-Failure Warranty using S.M.A.R.T technology
We pioneered failure-prediction technology for disk drives by developing monitoring tests run by Smart
Array controllers. Called Monitoring and Performance (M&P) or Drive Parameter Tracking, Smart Array
controllers externally monitor disk drive attributes such as seek times, spin-up times, and media defects to
detect changes that could indicate potential failure.
We worked with the disk drive industry to help develop a diagnostic and failure prediction capability
known as Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.). As S.M.A.R.T. matured, we
used both M&P and S.M.A.R.T. to predict disk drive failures.
S.M.A.R.T. has matured to the point that we rely exclusively on this technology to predict disk drive failure
to support Pre-Failure Warranty. Since 1997, all HP SCSI, SAS, and SATA server-class disk drives have
incorporated S.M.A.R.T. technology. S.M.A.R.T. disk drives inform the host when a disk drive is
experiencing abnormal operation likely to lead to drive failure.
S.M.A.R.T. places the monitoring capabilities within the disk drive itself. These monitoring routines are more
accurate than the original M&P tests because they have direct access to internal performance, calibration,
and error measurements for a specific drive type.
HP Smart Array controllers scan the disk drive media during idle time and rep air, or report, any media
defects detected. The controllers recognize S.M.A.R.T. error codes and notify HP Systems Insight Manager
(SIM) of a potential problem. HP SIM notifies administrators of drive failures.
Automatic data recovery with rapid rebuild technology
When you replace a disk drive in an array, Smart Array controllers use the fault-tolerance information on
the remaining drives in the array to reconstruct the missing data and write it to the replacement drive. If a
drive fails during the rebuild, the reconstruction fails and the data is likely to be permanently lost.