Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Glossary
rolling disaster
Glossary 435
Primary Cluster A cluster in production
that has packages protected by the HP
ContinentalClusters product.
primary package The package that
normally runs on the Primary Cluster in a
production environment.
pushbutton failover Use of the
cmrecovercl command to allow all package
recovery groups to start up on the Recovery
Cluster following a significant cluster event
on the Primary Cluster.
PV links A method of LVM configuration
that allows you to provide redundant disk
interfaces and buses to disk arrays, thereby
protecting against single points of failure in
disk cards and cables.
PVOL A primary volume configured in an
XP series disk array that uses Continuous
Access. PVOLs are the primary copies in
physical data replication with Continous
Access on the XP.
Q
quorum See See cluster quorum.
quorum server A cluster node that acts as
a tie-breaker in a disaster tolerant
architecture in case all of the nodes in a data
center go down at the same time. See also
arbitrator.
R
R1 The Symmetrix term indicating the data
copy that is the primary copy.
R2 The Symmetrix term indicating the
remote data copy that is the secondary copy.
It is normally read-only by the nodes at the
remote site.
Recovery Cluster A cluster on which
recovery of a package takes place following a
failure on the Primary Cluster.
recovery group failover A failover of a
package recovery group from one cluster to
another.
recovery package The package that takes
over on the Recovery Cluster in the event of
a failure on the Primary Cluster.
regional disaster A disaster, such as an
earthquake or hurricane, that affects a large
region. Local, campus, and proximate
metropolitan clusters are less likely to
protect from regional disasters.
remote failover Failover to a node at
another data center or remote location.
resynchronization The process of making
the data between two sites consistent and
current once systems are restored following
a failure. Also called data resynchronization.
rolling disaster A second disaster that
occurs before recovering from a previous
disaster, e.g. while data is being
synchronized between two data centers after
a disaster, one of the data centers fails,
interrupting the data synchronization
process. Rolling disasters may result in data
corruption that requires a reload from tape
backups.