HP serviceguard t2808-90006 manual Two Data Center and Quorum Service Location Architectures

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Building an Extended Distance Cluster Using Serviceguard and Software RAID

Two Data Center and Quorum Service Location Architectures

•Fibre Channel Direct Fabric Attach (DFA) is recommended over Fibre Channel Arbitrated loop configurations, due to the superior performance of DFA, especially as the distance increases. Therefore Fibre Channel switches are recommended over Fibre Channel hubs.

•Any combination of the following Fibre Channel capable disk arrays may be used: HP StorageWorks 1000 and 1500 series Modular Storage Arrays, HP StorageWorks Enterprise Virtual Arrays, or HP StorageWorks Disk Array XP.

•For disaster tolerance, application data must be mirrored between the primary data centers. You must ensure that the mirror copies reside in different data centers, as the software cannot determine the locations.

NOTE	When a failure results in the mirror copies losing synchronization,
	MD will perform a full resynchronization when both halves of the
	mirror are available.

•No routing is allowed for the networks between data centers. Routing is allowed to the third data center if a Quorum Server is used in that data center.

The following is a list of recommended arbitration methods for Extended Distance Cluster solutions in order of preference:

•Quorum Server running in a Serviceguard cluster

•Quorum Server

For more information on Quorum Server, see the Serviceguard Quorum Server Release Notes for Linux.

Figure 2-1 is an example of a two data center and third location configuration using DWDM, with a quorum server node on the third site.

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Chapter 2

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Contents Page Legal Notices Contents Disaster Scenarios and Their Handling Managing an MD Device Contents Contents Printing History Editions and ReleasesHP Printing Division Intended Audience Document OrganizationPage Related Page Disaster Tolerance Evaluating the Need for Disaster Tolerance Evaluating the Need for Disaster Tolerance Node 1 fails What is a Disaster Tolerant Architecture?High Availability Architecture Pkg B Client ConnectionsDisaster Tolerant Architecture Understanding Types of Disaster Tolerant Clusters Extended Distance ClustersFrom both storage devices Extended Distance Cluster Two Data Center Setup Benefits of Extended Distance Cluster Cluster Extension CLX Cluster Shows a CLX for a Linux Serviceguard cluster architecture CLX for Linux Serviceguard ClusterBenefits of CLX Differences Between Extended Distance Cluster and CLX Continental Cluster Data Cent er a Data Center B Los Angeles ClusterNew York Cluster Continental ClusterBenefits of Continentalclusters Comparison of Disaster Tolerant Solutions Continental Cluster With Cascading FailoverContinentalclusters Comparison of Disaster Tolerant Cluster SolutionsAttributes Extended Distance Cluster HP-UX onlyUnderstanding Types of Disaster Tolerant Clusters Understanding Types of Disaster Tolerant Clusters Understanding Types of Disaster Tolerant Clusters WAN EVA Disaster Tolerant Architecture Guidelines Protecting Nodes through Geographic DispersionProtecting Data through Replication Off-line Data ReplicationOn-line Data Replication Physical Data ReplicationAdvantages of physical replication in hardware are Disadvantages of physical replication in hardware areAdvantages of physical replication in software are Disadvantages of physical replication in software are Logical Data ReplicationDisadvantages of logical replication are Using Alternative Power Sources Ideal Data ReplicationData Center a Node 3 Power Circuit Alternative Power SourcesPower Circuit 1 node Creating Highly Available NetworkingDisaster Tolerant Local Area Networking Disaster Tolerant Wide Area NetworkingDisaster Tolerant Cluster Limitations Manage it in-house, or hire a service? Managing a Disaster Tolerant EnvironmentHow is the cluster maintained? Additional Disaster Tolerant Solutions Information Building an Extended Distance Types of Data Link for Storage Networking DwdmTwo Data Center and Quorum Service Location Architectures Two Data Center and Quorum Service Location Architectures Two Data Centers and Third Location with Dwdm and Quorum ServerTwo Data Center and Quorum Service Location Architectures Rules for Separate Network and Data Links Guidelines on Dwdm Links for Network and Data Guidelines on Dwdm Links for Network and Data Guidelines on Dwdm Links for Network and Data Chapter Configuring your Environment Understanding Software RAID Supported Operating Systems Installing the Extended Distance Cluster SoftwareInstalling XDC PrerequisitesVerifying the XDC Installation # rpm -Uvh xdc-A.01.00-0.rhel4.noarch.rpmInstalling the Extended Distance Cluster Software Configuring the Environment Configuring the Environment Configuring the Environment Configuring Multiple Paths to Storage Setting the Value of the Link Down Timeout ParameterCluster Reformation Time and Timeout Values Using Persistent Device Names Http//docs.hp.comCreating a Multiple Disk Device To Create and Assemble an MD Device# mdadm -A -R /dev/md0 /dev/hpdev/sde1 /dev/hpdev/sdf1 Chapter Linux #RAIDTAB= # MD RAID Commands Creating and Editing the Package Control Scripts To Create a Package Control ScriptTo Edit the Datarep Variable To Edit the Xdcconfig File parameter To Configure the RAID Monitoring ServiceEditing the raid.conf File Cases to Consider when Setting Rpotarget RPO Target Definitions Chapter Multipledevices and Componentdevices Raidmonitorinterval Configuring your Environment for Software RAID What happens when this disaster occurs Recovery ProcessDisaster Scenario Disaster Scenarios and Their Handling Disaster Scenarios and Their Handling# mdadm --remove /dev/md0 # mdadm -add /dev/md0 Dev/hpdev/mylink-sdf P1 uses a mirror md0 Run the following command to S2 is non-current by less # cmrunpkg packagename Execute the commands that With md0 consisting of only N1, for example Becomes accessible from N2 Center Disaster Scenarios and Their Handling Managing an MD Device Viewing the Status of the MD Device Cat /proc/mdstatStopping the MD Device Example A-1 Stopping the MD Device /dev/md0Starting the MD Device Example A-2 Starting the MD Device /dev/md0Removing and Adding an MD Mirror Component Disk # udevinfo -q symlink -n sdc1Adding a Mirror Component Device # mdadm --remove /dev/md0 /dev/hpdev/sdeIndex 104