Adaptec 7220ss User Guide

Glossary

active-active
Active-active mode is when two controllers in a storage system 
cooperate to provide redundancy. If one controller fails, the 
remaining controller takes over. To accomplish this, each controller 
has two host ports, one of which is normally active, the other 
normally passive. In a failed-over configuration, the passive port 
becomes active and assumes the identity of the failed controller. In 
active-active mode, arrays can be accessed only by the controller 
that currently owns them. One controller will have no visibility to 
the other controller’s arrays. If a controller fails, the surviving 
controller will take ownership of all arrays. Disk drives in the spare 
pool and unassigned disk drives are visible to both controllers. See 
also 

.

array
Two or more physical disk drives grouped together to appear as a 
single device (logical drive) to the user. Also known as a container. 
See also 

bus
See 

channel
Any path used for the transfer of data and the control of 
information between storage devices and a storage controller. Each 
controller’s channels are identified by a number. Also known as a 
bus.