HP Smart Array 6400 Series Controllers Support Guide, September 2007

and Ultra2 drives are installed on the same bus with the Smart Array Controllers, individual
drives operate at their respective supported speeds (Ultra320, Ultra160 and Ultra2).
Fault Management Features
The Smart Array Controllers and the HP-UX operating system support several fault management
and data reliability features that minimize the impact of disk drive defects on your systems.
Auto-Reliability Monitoring (ARM) A firmware process that operates in the background,
scanning physical disks for bad sectors in fault-tolerant
logical drives. ARM also verifies the consistency of parity
data in logical drives that use RAID 5 or RAID ADG. This
process assures that you can recover all data successfully
if a disk fails. ARM operates only when you select a
fault-tolerant configuration.
Dynamic sector repair Automatically remaps any sectors that have media faults
detected either during normal operation or by auto
reliability monitoring.
S.M.A.R.T. An industry-standard diagnostic and failure prediction
feature of physical disks, developed by HP in collaboration
with the disk drive industry. S.M.A.R.T. monitors several
factors that predict imminent physical disk failure due to
mechanical causes. These include the condition of the
read/write head, the seek error rate, and the spin-up time.
When a threshold value is exceeded for one of these factors,
the disk sends an alert to the controller that failure is
imminent. Thus, you can back up data and replace the disk
drive before failure occurs.
NOTE: An online spare does not become active and start
rebuilding when an imminent failure alert is sent, because
the degraded disk has not failed yet and is still online. The
online spare is activated only after a disk in an array has
failed.
Drive failure alert features Send an alert message to Event Monitoring Services (EMS)
when a physical disk or a logical drive fails.
Interim data recovery Occurs if a disk fails in a fault-tolerant configuration.
Recovery ROM A redundancy feature that ensures continuous system
availability by providing a backup ROM. This feature
protects against corruption of a ROM image (for example,
by power fluctuation during ROM upgrade). If corruption
occurs, the server automatically restarts using the
remaining good copy of the ROM image. When you
upgrade the ROM, the inactive image (the one not being
used by the system) is upgraded. There is not normally
any noticeable difference in operation. When you use
Recovery ROM for the first time, however, both ROM
images are upgraded, causing a boot delay of about 60
seconds.
20 Smart Array 6400 Series Controller Overview