Installation guide

Glossary
Glossary-8 DAC960PG Installation Guide
Session
Refers to the period of time between any two consecutive system shutdowns.
System shutdown may be either a power off/on, or a hardware reset.
Standard Disk Drive
This term refers to a hard disk drive with SCSI, IDE, or other interface, that
is attached to the host system through a standard disk controller.
Standby Replacement of Disks (“Hot Spare”)
The “Standby Replacement” (or “Hot Spare”) is one of the most important
features the controller provides to achieve automatic, non-stop service with a
high degree of fault-tolerance. The rebuild operation will be carried out by
the controller automatically when a SCSI disk drive fails and both of the
following conditions are true:
• A “standby” SCSI disk drive of identical size is found attached to the
same controller;
• All of the system drives that are dependent on the failed disk are
redundant system drives, e.g., RAID 1, RAID 3, RAID 5, RAID 0+1.
☛
Note
The standby rebuild will only happen on the SAME
DAC960 controller, never across DAC960
controllers.
A “Standby” disk can be created in one of two ways:
3. When a user runs DACCF utility, all disks attached to the controller
that are NOT configured into any drive group will be automatically
labeled as “standby” drives.
4. A disk may also be added (attached at a later time) to a running system
and labeled as standby by using the “DAC960 Software Kit” (see
appropriate chapters for DAC960 utilities for a particular operating
system).