Understanding Svc Terminology; Node; I/O Group; Cluster - Cisco MDS 9216 Configuration Manual

Chapter 2 Getting Started

Understanding SVC Terminology

This section defines frequently-used SVC terms that are necessary to proceed with the configuration
process (see
Figure 2-1

I/O Group

Node

An instance of SVC that is running in the CSM. A CSM consists of two completely independent nodes.
Each node is represented by an interface.
I/O group
SVC nodes are always used in pairs. A pair of SVC nodes is called an I/O group. The nodes in a given
I/O group must reside in two separate CSMs. An I/O group acts as a storage controller in the fabric.

Cluster

A cluster can contain multiple I/O groups. All nodes in the cluster must run the same SVC image version.
The IP address for a cluster must be assigned in the same subnet as the management interface.

MDisk

A representation of back end storage. Each cluster is configured so all the nodes in a cluster see the same
set of MDisks.

VDisk

A virtual representation of a LUN that is exposed by the cluster to the hosts in a SAN. Each VDisk is
independently associated with a single I/O group.
78-16119-01, Cisco MDS SAN-OS Release 1.3
Figure 2-1).
Graphical Representation of SVC Terms
Node 1
CSM 1
Node 1
CSM 2
Vdisk 1
Mdisk group
Node 2
I/O Group
Node 2
Vdisk 2
Mdisk group
Cisco MDS 9000 Family SAN Volume Controller Configuration Guide
Understanding SVC Terminology
Vdisk 3
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