HP Smart Array 6400 Series Controllers Support Guide, September 2007

E Frequently Asked Questions
Smart Array 6400 Series Controller FAQ
Q: Are simultaneous internal and external connections supported for one channel?
A: No, simultaneous internal and external connections are not supported for one channel. For
example, you cannot have both an internal connection for channel A and an external connection
for channel A. However, you can have an internal connection for channel A and an external
connection for channel B.
Q: How many Smart Array Controllers can I install in my system?
A: The maximum number of controllers that you can install depends on the system and several
other factors specific to your configuration.
The maximum number of controllers is restricted to the number of PCI-X or PCI slots not used
for other peripherals. The power rating of the system also limits the number of controllers. Each
Smart Array Controller requires 12 -18 W. The system must be capable of supplying each controller
with 12 -18 W.
See the documentation for your system for more information.
Q: How many external drives can I attach to my system?
A: Each channel of a Smart Array controller supports up to 14 disk drives. The Smart Array 6402
has two channels supporting up to 28 disks. The Smart Array 6404 has four channels supporting
up to 56 disks.
Q: Does the Smart Array 6402 Series Controller support SCSI tape drives and CD-ROM drives?
A: No
Q: What is the data transfer rate for the Smart Array Controllers?
A: Each channel of the Smart Array Controller supports Ultra320 speeds. Ultra320 SCSI has a
bandwidth of 320 MB/s. Most server applications do not take advantage of the full Ultra320
bandwidth, so performance results vary from system to system.
Q: What is the difference between LVD and Ultra320 SCSI?
A: Low Voltage Differential (LVD) is a signaling level for SCSI protocols. Ultra320 is a SCSI
protocol that uses LVD signaling. Ultra60 and Ultra2 also use LVD signaling, but earlier SCSI
protocols use Single-Ended (SE) signaling.
Q: I have several hard drives in my server and in an HP StorageWorks Enclosure 4300. What
SCSI IDs do I assign for these drives?
A: If you are using hot-pluggable disks in a StorageWorks 4300 series enclosure, or an MSA 30,
the SCSI IDs are set automatically according to the bay in which the drives are installed and do
not need to be set manually.
Non-hot-pluggable disks must each have a unique SCSI ID value ranging from 0 to 15. Do not
use ID 7, which is reserved for controller use. The SCSI ID value determines the priority given
to the device when it attempts to use the SCSI bus.
Q: Can I use third-party (non-HP) drives with the Smart Array 6402 Controller?
A: No.
Q: Why do the drive activity LEDs light up on some drives when my system is idle?
A: The Smart Array 6402 Series Controller performs background activities on the drives when
the controller is otherwise idle. For example, Auto-Reliability Monitoring (ARM) scans
fault-tolerant volumes for defects and verifies the consistency of parity data, and Drive Parameter
Tracking periodically checks the performance of all drives on the controller (normally on an
hourly basis).
Q: What is RAID ADG?
A: RAID ADG is an extension of RAID 5 that enables additional fault tolerance by using two
different and independent parity schemes. Data is striped across a set of hard drives, just as with
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