HP Netserver L Server series - Manual (Page 39)

Chapter 6 Installing Mass Storage Devices
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Hot-Swap Mass Storage
The Ultra2 SCSI hot-swap hard disk drives for mass storage come in two heights:
the 1-inch low-profile drive and the 1.6-inch half-height drive.
The Ultra2 drives are LVD (low voltage differential) drives, which allow the
integration of the differential drivers and receivers into SCSI drive controllers.
Ultra2 technology provides increased signal quality and ensures the same data
integrity as the previous high voltage differential designs at a reduced cost. With
the low voltage design, the SCSI bus cable can extend up to 12 meters.
CAUTION Do not mix devices with high voltage differential (HVD)
drivers and receivers and devices with SE, Ultra2 or
multimode drivers and receivers on the same SCSI bus. I/O
circuits used by devices with SE, Ultra2 or multimode drivers
and receivers do not operate at HVD levels and should never
be exposed to HVD environments. If you mix SCSI SE and
SCSI Ultra2 devices, system performance will be adversely
affected. For best performance, use only Ultra2 devices.
Each Ultra2 disk drive module has two LED apertures: one for power status and
one for activity status. Light pipes on the module transmit light to these apertures
from LEDs on the inside rear of the hot-swap mass storage cage. The display
meanings are described in Table 6-2.
Table 6-2. Hard Disk Drive LED Indications
Power Status LED Activity Status LED
Off: Disk not present, or not
connected to the cage Off: No disk activity
Green (solid): Disk present Green (flashing): Accessing disk
Green (Solid for more than one minute):
Disk spinning up, or "hung"
Amber (flashing): Disk failure predicted
Red (solid): Disk failed