Avago Technologies Syncro CS 9271-8i - Manual (Page 6)

LSI Corporation
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Syncro CS 9271-8i Solution User Guide
October 2013 Chapter 1: Introduction
HA-DAS Terminology
Node downtime in an HA system can be either planned and unplanned. Planned node downtime is the result of
management-initiated events, such as upgrades and maintenance. Unplanned node downtime results from events
that are not within the direct control of IT administrators, such as failed software, drivers, or hardware. The Syncro CS
9271-8i solution protects your data and maintains system up-time from both planned and unplanned node
downtime. It also enables you to schedule node downtime to update hardware or firmware, and so on. When you
bring one controller node down for scheduled maintenance, the other node takes over with no interruption of
service.
1.2 HA-DAS Terminology
This section defines some additional important HA-DAS terms.
 Cache Mirror: A cache coherency term describing the duplication of write-back cached data across two
controllers.
 Exclusive Access: A host access policy in which a VD is only exposed to, and accessed by, a single specified server.
 Failover: The process in which the management of drive groups and VDs transitions from one controller to the
peer controller to maintain data access and availability.
 HA Domain: A type of storage domain that consists of a set of HA controllers, cables, shared disk resources, and
storage media.
 Peer Controller: A relative term to describe the HA controller in the HA domain that acts as the failover controller.
 Server/Controller Node: A processing entity composed of a single host processor unit or multiple host processor
units that is characterized by having a single instance of a host operating system.
 Server Storage Cluster: An HA storage topology in which a common pool of storage devices is shared by two
computer nodes through dedicated Syncro CS 9271-8i controllers.
 Shared Access: A host access policy in which a VD is exposed to, and can be accessed by, all servers in the HA
domain.
 Virtual Drive (VD): A storage unit created by a RAID controller from one or more physical drives. Although a
virtual drive can consist of multiple drives, it is seen by the operating system as a single drive. Depending on the
RAID level used, the virtual drive might retain redundant data in case of a drive failure.
1.3 Syncro CS 9271-8i Solution Features
The Syncro CS 9271-8i solution supports the following HA features.
 Server storage cluster topology, enabled by the following supported operating systems:
— Microsoft® Windows Server®2008 R2
— Microsoft Windows Server 2012
— Red Hat® Enterprise Linux 6.3
— Red Hat Enterprise Linux 6.4
— SuSE® Linux Enterprise Server 11 SP3
— SuSE Linux Enterprise Server 11 SP2
 Clustering/HA services support:
— Microsoft failover clustering
— Red Hat High Availability Add-on
— SuSE High Availability Extensions
 Dual-active HA with shared storage
 Controller-to-controller intercommunication over SAS