Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF

E, F
Environment File Metrocluster uses a configuration file that includes variables that define the environment for the
Metrocluster to operate in a Serviceguard cluster. This configuration file is referred to as the
Metrocluster environment file. This file needs to be available on all the nodes in the cluster for
Metrocluster to function successfully.
ESCON Enterprise Storage Connect. A type of fiber-optic channel used for inter-frame communication
between EMC Symmetrix frames using EMC SRDF or between HP StorageWorks E P9000 or XP
series disk array units using Continuous Access P9000 or XP.
failback Failing back from a backup node, which may or may not be remote, to the primary node that
the application normally runs on.
failover The transfer of control of an application or service from one node to another node after a failure.
Failover can be manual, requiring human intervention, or automated, requiring little or no human
intervention.
G
gatekeeper A small EMC Symmetrix device configured to function as a lock during certain state change
operations.
H - L
local failover Failover on the same node; this is most often applied to hardware failover, for example local
LAN failover is switching to the secondary LAN card on the same node after the primary LAN
card has failed.
LUN (Logical Unit Number) A SCSI term that refers to a logical disk device composed of one or more
physical disk mechanisms, typically configured into a RAID level.
M
M by N A type of Symmetrix grouping in which up to two Symmetrix frames may be configured on either
side of a data replication link in a Metrocluster with EMC SRDF configuration. M by N
configurations include 1 by 2, 2 by 1, and 2 by 2.
manual failover Failover requiring human intervention to start an application or service on another node.
Metrocluster A Hewlett-Packard product that allows a customer to configure a Serviceguard cluster as a disaster
recovery metropolitan cluster.
Metrocluster
Environment File
Metrocluster uses a configuration file that includes variables that define the environment for the
Metrocluster to operate in a Serviceguard cluster. This configuration file is referred to as the
Metrocluster environment file. This file needs to be available on all the nodes in the cluster for
Metrocluster to function successfully.
N
notification A message that is sent following a cluster or package event.
O, P
physical data
replication
An on-line data replication method that duplicates I/O writes to another disk on a physical block
basis. Physical replication can be hardware-based where data is replicated between disks over
a dedicated link (for example EMC’s Symmetrix Remote Data Facility or the HP StorageWorks E
Disk Array XP Series Continuous Access), or software-based where data is replicated on multiple
disks using dedicated software on the primary node (for example, MirrorDisk/UX).
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.
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