User's Manual

disk replacement
delay
The time that elapses between a drive failure and when the controller starts searching for spare
disk space. Drive replacement seldom starts immediately in case the “failure” was a glitch or
temporary condition.
drive blank See disk drive blank.
drive enclosure A unit that holds storage system devices such as disk drives, power supplies, blowers, I/O modules,
transceivers, or EMUs.
drive enclosure See drive enclosure.
drive enclosure
event
A significant operational occurrence involving a hardware or software component in the drive
enclosure. The drive enclosure EMU reports these events to the controller for processing.
dual power supply
configuration
See redundant power configuration.
dual-loop A configuration where each drive is connected to a pair of controllers through two loops. These
two Fibre Channel loops constitute a loop pair.
dynamic capacity
expansion
A storage system feature that provides the ability to increase the size of an existing virtual disk.
Before using this feature, you must ensure that your operating system supports capacity expansion
of a virtual disk (or LUN).
E
EIA Electronic Industries Alliance. A standards organization specializing in the electrical and functional
characteristics of interface equipment.
EIP Event Information Packet. The event information packet is an HSV element hexadecimal character
display that defines how an event was detected. Also called the EIP type.
electromagnetic
interference
See EMI.
electrostatic
discharge
See ESD.
element In a drive enclosure, a device such as an EMU, power supply, disk, blower, or I/O module.
The object can be controlled, interrogated, or described by the enclosure services process.
1.
2. In the Open SAN Manager, a controllable object, such as the Enterprise storage system.
EMI Electromagnetic Interference. The impairment of a signal by an electromagnetic disturbance.
EMU Environmental Monitoring Unit. An element which monitors the status of an enclosure, including
the power, air temperature, and blower status. The EMU detects problems and displays and
reports these conditions to a user and the controller. In some cases, the EMU implements corrective
action.
enclosure A unit used to hold various storage system devices such as disk drives, controllers, power supplies,
blowers, an EMU, I/O modules, or blowers.
enclosure address
bus
An Enterprise storage system bus that interconnects and identifies controller enclosures and disk
drive enclosures by their physical location. Enclosures within a reporting group can exchange
environmental data. This bus uses enclosure ID expansion cables to assign enclosure numbers to
each enclosure. Communications over this bus do not involve the Fibre Channel drive enclosure
bus and are, therefore, classified as out-of-band communications.
enclosure number
(En)
One of the vertical rack-mounting positions where the enclosure is located. The positions are
numbered sequentially in decimal numbers starting from the bottom of the cabinet. Each disk
enclosure has its own enclosure number. A controller pair shares an enclosure number. If the
system has an expansion rack, the enclosures in the expansion rack are numbered from 15 to
24, starting at the bottom.
enclosure services Those services that establish the mechanical environmental, electrical environmental, and external
indicators and controls for the proper operation and maintenance of devices with an enclosure
as described in the SES SCSI-3 Enclosure Services Command Set (SES), Rev 8b, American National
Standard for Information Services.
Enclosure Services
Interface
See ESI.
166 Glossary