Administrator Guide

A
AccessAnywhere
The breakthrough technology that enables metro node clusters to provide access to information between clusters that are
separated by distance.
active/active
A cluster with no primary or standby servers, because all servers can run applications and interchangeably act as backup for one
another.
active/passive
A powered component that is ready to operate upon the failure of a primary component.
Active Directory
A directory service included in most Windows Server operating systems. AD authenticates and authorizes users and computers
in a network of Windows domain type.
active mirror
A copy of data that is part of a local or remote mirroring service.
B
backend port
Metro node director port connected to storage arrays (acts as an initiator).
bandwidth
The range of transmission frequencies a network can accommodate, expressed as the difference between the highest and
lowest frequencies of a transmission cycle. High bandwidth allows fast or high volume transmissions.
bias
When a cluster has the bias for a given DR1, it continues to service I/O to volumes on that cluster if connectivity to the remote
cluster is lost (due to cluster partition or cluster failure). The bias for a specific volume is determined by the detach rules for the
volume, the detach rules for the consistency group (if the volume is a member of a consistency group) and metro node Witness
(if metro node Witness is deployed).
bit
A unit of information that has a binary digit value of either 0 or 1.
block
The smallest amount of data that can be transferred following SCSI standards, which is traditionally 512 bytes. Virtual volumes
are presented to users as a contiguous lists of blocks.
block size
The actual size of a block on a device.
Bookmark
A label applied to a snapshot so that the snapshot can be explicitly called (identified) during recovery processes (during image
access). Bookmarks are created through the CLI or GUI and can be created manually, by the user, or automatically, by the
system. Bookmarks created automatically can be created at
pre-defined intervals or in response to specific system events. Parallel bookmarks are bookmarks that are created
simultaneously across multiple consistency groups.
byte
Memory space used to store eight bits of data.
Glossary
32 Glossary