HP serviceguard t2808-90006 manual Configuring the Environment

Page 67

Configuring your Environment for Software RAID

Configuring the Environment

that are of identical sizes. Differences in disk set size results in a mirror being created of a size equal to the smaller of the two disks. Be sure to create the mirror using the persistent device names of the component devices. For more information on creating and managing a mirrored device, see “Creating a Multiple Disk Device” on page 72.

4.Create volume groups and logical volumes on the MD mirror device

Once the MD mirror device is created, you need to create volume groups and logical volumes on it. You must use the Volume Group Exclusive activation feature. This protects against a volume group which is already active on one node to be activated again (accidentally or on purpose) on any other node in the cluster. For more information on creating volume groups and configuring exclusive activation, see “Creating Volume Groups and Configuring VG Exclusive Activation on the MD Mirror” on page 74.

5.Configure the package control script and the Extended Distance cluster configuration script

In order to let Serviceguard know of the existence of the mirror created in the previous step and hence make use of it, it must be configured as part of a package. This MD device must be specified in the Extended Distance Cluster configuration file raid.conf. Copy the raid.conf.template in the software bundle as raid.conf to the package directory and edit it to specify the RAID configuration parameters for this package. Using the details mentioned in this file Serviceguard will start, stop and monitor this MD mirror for the package. For details on how to configure the package control script and raid.conf see “Configuring the Package Control Script and RAID Configuration File” on page 76.

IMPORTANT	Every time you edit the raid.conf file, you must copy this edited file
	to all nodes in the cluster.

6.Start the package

Starting a package configured for Software RAID is the same as starting any other package in Serviceguard for Linux.

You also need to keep in mind a few guidelines before you enable Software RAID for a particular package. Following are some of these guidelines you need to follow:

Chapter 3

67

Image 67

Contents Page Legal Notices Contents Disaster Scenarios and Their Handling Managing an MD Device Contents Contents Editions and Releases Printing HistoryHP Printing Division Document Organization Intended AudiencePage Related Page Disaster Tolerance Evaluating the Need for Disaster Tolerance Evaluating the Need for Disaster Tolerance Pkg B Client Connections What is a Disaster Tolerant Architecture?High Availability Architecture Node 1 failsDisaster Tolerant Architecture Extended Distance Clusters Understanding Types of Disaster Tolerant ClustersFrom both storage devices Extended Distance Cluster Two Data Center Setup Benefits of Extended Distance Cluster Cluster Extension CLX Cluster CLX for Linux Serviceguard Cluster Shows a CLX for a Linux Serviceguard cluster architectureBenefits of CLX Differences Between Extended Distance Cluster and CLX Continental Cluster Continental Cluster Los Angeles ClusterNew York Cluster Data Cent er a Data Center BBenefits of Continentalclusters Continental Cluster With Cascading Failover Comparison of Disaster Tolerant SolutionsCluster HP-UX only Comparison of Disaster Tolerant Cluster SolutionsAttributes Extended Distance ContinentalclustersUnderstanding Types of Disaster Tolerant Clusters Understanding Types of Disaster Tolerant Clusters Understanding Types of Disaster Tolerant Clusters WAN EVA Protecting Nodes through Geographic Dispersion Disaster Tolerant Architecture GuidelinesOff-line Data Replication Protecting Data through ReplicationPhysical Data Replication On-line Data ReplicationDisadvantages of physical replication in hardware are Advantages of physical replication in hardware areAdvantages of physical replication in software are Logical Data Replication Disadvantages of physical replication in software areDisadvantages of logical replication are Ideal Data Replication Using Alternative Power SourcesCreating Highly Available Networking Alternative Power SourcesPower Circuit 1 node Data Center a Node 3 Power CircuitDisaster Tolerant Wide Area Networking Disaster Tolerant Local Area NetworkingDisaster Tolerant Cluster Limitations Managing a Disaster Tolerant Environment Manage it in-house, or hire a service?How is the cluster maintained? Additional Disaster Tolerant Solutions Information Building an Extended Distance Dwdm Types of Data Link for Storage NetworkingTwo Data Center and Quorum Service Location Architectures Two Data Center and Quorum Service Location Architectures Server Two Data Centers and Third Location with Dwdm and QuorumTwo 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 Prerequisites Installing the Extended Distance Cluster SoftwareInstalling XDC Supported Operating Systems# rpm -Uvh xdc-A.01.00-0.rhel4.noarch.rpm Verifying the XDC InstallationInstalling the Extended Distance Cluster Software Configuring the Environment Configuring the Environment Configuring the Environment Setting the Value of the Link Down Timeout Parameter Configuring Multiple Paths to StorageCluster Reformation Time and Timeout Values Http//docs.hp.com Using Persistent Device NamesTo Create and Assemble an MD Device Creating a Multiple Disk Device# mdadm -A -R /dev/md0 /dev/hpdev/sde1 /dev/hpdev/sdf1 Chapter Linux #RAIDTAB= # MD RAID Commands To Create a Package Control Script Creating and Editing the Package Control ScriptsTo Edit the Datarep Variable To Configure the RAID Monitoring Service To Edit the Xdcconfig File parameterEditing the raid.conf File Cases to Consider when Setting Rpotarget RPO Target Definitions Chapter Multipledevices and Componentdevices Raidmonitorinterval Configuring your Environment for Software RAID Recovery Process What happens when this disaster occursDisaster 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 Cat /proc/mdstat Viewing the Status of the MD DeviceExample A-1 Stopping the MD Device /dev/md0 Stopping the MD DeviceExample A-2 Starting the MD Device /dev/md0 Starting the MD Device# udevinfo -q symlink -n sdc1 Removing and Adding an MD Mirror Component Disk# mdadm --remove /dev/md0 /dev/hpdev/sde Adding a Mirror Component DeviceIndex 104