Power Supplies; Data Integrity; Status Monitoring And Display; Enclosure Layout - Compaq 4200 User Manual

1–4 Compaq StorageWorks Enclosure 4200 Family LVD Disk Enclosure User Guide

Power Supplies

In a single power supply configuration, the failure of a power supply disables the
enclosure. Use the optional redundant power supply configuration to prevent this. In this
configuration, the failure of a single power supply or blower does not disable the
enclosure.

Data Integrity

Data integrity could be compromised if data transfers occur when there is no DC power to
the I/O module or the drives, To avoid inducing errors, the power pins on these elements
are longer than the data pins. This ensures that power is always present when a data
transfer occurs.

Status Monitoring and Display

The major status monitoring capabilities of these enclosures include:
Displaying the enclosure status on the enclosure LEDs
Displaying the element status on the power supply, EMU, drive, and I/O module LEDs
Detecting the installation of a blower, power supply, disk drive, or I/O module
Detecting the blower removal of a blower, power supply, disk drive, or I/O module
Sensing enclosure temperatures
Sensing power supply voltage, current, and total power

Enclosure Layout

The physical layout of the enclosure is the same in a rack or a tower. The drives mount in
the bays in the front of the enclosure. These bays are numbered from the left (bay
the right (see Figure 1–5 and Figure 1–3). The common method of referring to a drive is
by the bay number. The drive in bay
forth.
is drive 1, the drive in bay
CAUTION: There is no direct correlation between the bay number and SCSI bus ID.
The SCSI bus IDs are a function of the bus type (single or dual) and the number of
drives See Chapter 3 for SCSI bus IDs.
) to
is drive 8, and so