HP Cluster Software manual Failover error handling

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Failover error handling

Windows Cluster automatically fails over resource groups if the system where resource group is running on becomes unavailable. This is part of the cluster functionality. Also, this means that if a problem occurs with the HP 3PAR storage system, a resource group online process will be stopped. The behavior of HP 3PAR Cluster Extension is highly configurable. Depending upon the customer setting, Cluster Extension is used to prevent resource groups from going online automatically under the wrong conditions.

Cluster Extension will return local, data center-wide or even cluster-wide errors to prevent accidental access to the resource group’s virtual volumes. HP does not recommend restarting a failed resource group without investigating the problem. A failed Cluster Extension resource indicates the need to check the status of the Remote Copy volume group and its member virtual volumes and decide whether it is safe to continue or not.

HP 3PAR Cluster Extension services, resources, or resource groups return a data center error and fail the resource if the Remote Copy volume group status indicates that the problem experienced locally would not be solved on another system connected to the same HP 3PAR storage system.

Depending on the resource group and resource property values, the resource tries to start on different nodes several times. If the remote data center is down, this would look like the resource group is alternating between the surviving systems. This happens until the previously mentioned resource and resource group property values are reached or you disable the restarting of the resource. This could be also the case if the ApplicationStartup resource property has been set to FASTFAILBACK. If a 3PAR storage system state has been discovered that does not allow bringing the resource group online on any system in the cluster, a cluster error would be reported and the resource would fail on all systems. This could lead to the same behavior as described for a HP 3PAR Cluster Extension data center error.

Failing physical disk resources during online attempt of the resource group

When resource groups that use HP 3PAR Cluster Extension to failover Remote Copy volume group are brought online, physical disk resources may fail due to the following reasons:

•The physical disk resource does not have a dependency on its HP 3PAR Cluster Extension resources/packages configured. Review the setup steps for HP 3PAR Cluster Extension resources.

•The fibre channel path or connectivity between the servers and the storage systems may be broken. So user has to review the FC connectivity between the servers and the storage systems.

•If the storage array is brought back online or started after the array shutdown due to the datacenter disaster or Inform OS upgrade, at times the status of the remote copy volume group may go to the failsafe status as soon as the array is brought back online. The status of the remote copy volume group is marked as failsafe by the Inform OS after the array comes online and when the replication roles are primary at one side and primary-rev at the other side. At this time, the physical disk resource may fail to come online in the Microsoft failover cluster host whenever the cluster application role tries to come online on the server cluster host which is connected to the rebooted storage array.

One of the scenarios to get in to the failsafe status can be explained as follows.

The replication roles for a remote copy volume group are primary in one datacenter (primary) and secondary in the other datacenter (secondary) and the corresponding application in the Microsoft failover cluster are online in the primary datacenter. In case a disaster such as power outage happens in the primary datacenter, the application tries to failover to the failover cluster host in the secondary datacenter. The application comes online successfully in the failover cluster host in the secondary datacenter if the CLX property UseNonCurrentDataOk is set to Yes. Once application comes online, the replication role in the secondary datacenter turns to primary-rev from secondary.

Failover error handling

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Contents HP 3PAR Cluster Extension Software Administrator Guide Acknowledgments Contents CLI commands and utilities Support and other resources TroubleshootingGlossary Index CLI for easy integration Integration into cluster software Graphical user interfaceDisaster tolerance through geographical dispersion Metropolitan distance support Automated redirection of mirrored disksSynchronous mode support No server rebootStorage system configurations Fully Automatic Failover and FailbackTo-1 configuration To-1 configurationProcesses and components To-1 and 1-to-N configurationsHP 3PAR Remote Copy Remote Copy pairs Remote Copy volume groupsCluster setup considerations User configuration filePlanning for HP 3PAR Cluster Extension Force FlagNode Majority with File Share Witness 14 HP 3PAR Cluster Extension features HP 3PAR InForm Management Console or HP 3PAR InForm CLI Configuration tool clx3PARconfig.exeIP network considerations SAN fabric considerationsStarting the HP 3PAR Configuration Tool Configuring HP 3PAR Cluster ExtensionIntegrating HP 3PAR Cluster Extension with Msfc Defining the HP 3PAR configuration information using the GUI Configuring HP 3PAR Cluster Extension SystemUser.pwd Defining the HP 3PAR configuration information using the CLI Adding a HP 3PAR Cluster Extension resource Importing and exporting configuration informationExample Adding HP 3PAR Cluster Extension resource using cluster.exeChanging a HP 3PAR Cluster Extension resource name Configuring HP 3PAR Cluster Extension resourcesTIP Setting resource properties and values in the GUI Service or application properties and values Using Failover Cluster Management to set resource properties Make the necessary parameter changes, and then click OK Page Configuring cluster node data center assignments Configuring HP 3PAR storage system Changing Remote Copy volume group settings Selecting a volume groupConfiguring takeover actions Cluster resource clxfileshare /privprop Setting HP 3PAR Cluster Extension properties using a UCFSet-ClusterParameter -Name propertyname -Value valuetoset Adding dependencies on a HP 3PAR Cluster Extension resource Adding dependencies using Failover Cluster ManagementAdding dependencies using the PowerShell Adding dependencies using the CLICluster resource Disk32b00b /adddependencyclxfileshare Disaster-tolerant configuration example using a file share Configuration of HP 3PAR CLX for CSV disk on Windows ServerFour nodes host1DCA, host2DCA, host3DCB and host4DCB Service or application example Bringing a resource online Managing HP 3PAR Cluster Extension resourcesDisk3PARLUN25 \cluster resource Clxfileshare /ProP RestartAction=0Taking a resource offline Using Hyper-V Live Migration with HP 3PAR Cluster ExtensionDeleting a resource Creating array password file Bouncing service or applicationTiming considerations for Windows Clustering Msfc Administration Logs System resourcesHyper-V Live Migration log entries Configuring HP 3PAR Cluster Extension Page Configuring HP 3PAR Cluster Extension Windows Clustering User configuration fileFile structure ProgramFiles%\Hewlett-Packard\Cluster Extension 3PAR\confSpecifying object values Common objectsLogDir Application objectsLogLevel ApplicationDirApplicationStartup Optional Default %HPCLX3PARPATH% valuesClusterNotifyWaitTime ClusterNotifyCheckTimeDCAHosts Required DCBHosts RequiredRCVolumeGroupB Required RCVolumeGroupA RequiredDCA InServStorageSerNum Required DCB InServStorageSerNum RequiredResyncWaitTimeout Optional Sample configuration fileHP3PARCLICommandTimeout StatusRefreshIntervalPage Clx3PARrun CLI commandsConfiguring the HP 3PAR storage system Configuring the CLICreating the HP 3PAR Remote Copy environment Forceflag optionCreating and configuring the user configuration file Installing HP 3PAR InForm Command Line Interface CLITiming considerations Restrictions for customized implementations CSVDiskName String Synopsis\PSAdd-CSVDependencyOnCLX3PAR Outputs\PSAdd-CSVDependencyOnCLX3PAR -CSVDiskName Cluster Disk Related Links \PSAdd-VMDependencyOnCLX3PAR \PSAdd-VMDependencyOnCLX3PAR -CSVDiskName Cluster Disk Total virtual machines in the cluster residing on CSVRelated Links Name \PSGet-VMOnClusterSharedVolumeListForCLX3PAR Pre-execution and post-execution programs Post-execution return codes Pre-execution return codesLog facility LogsCLX cmdlet logs %HPCLX3PARPATH%\log\CLXCmdlet.log ProgramFiles%\Hewlett-Packard\Cluster Extension 3PAR\log\HP 3PAR Cluster Extension logs HP 3PAR storage system log or sysmgr log Error return codesRun showsys Log files Start errorsMsfc log file %windir\cluster\reports\cluster.log Failover error handling Echo rescan diskpart Cannot connect to HP 3PAR storage systemPing storage system network name or IP address Nslookup storage system network nameHost persona settings Change of HP 3PAR storage system IP or password fileNofailwrtonerr settings Cluster Extension Autopass troubleshooting Promote issueHP 3PAR Target arrays not configured with Remote Copy Links Remote Copy and 3PAR Virtual DomainsHP 3PAR Target arrays not configured with Remote Copy Links New and changed information in this edition Contacting HPRelated information WhitepapersDocument conventions Typographic conventionsGlossary Index SymbolsIndex Product manuals
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Cluster Software specifications

HP Cluster Software is a robust solution designed to enhance the reliability, availability, and scalability of computing environments in enterprise settings. This software is instrumental in managing clusters of servers, providing a unified framework that allows for efficient resource management, workload distribution, and high availability.

One of the main features of HP Cluster Software is its ability to deliver high availability through failover mechanisms. In the event of a hardware or software failure, the software automatically shifts workloads from the affected node to a standby node within the cluster, minimizing downtime. This feature is critical for organizations that require continuous access to their data and applications.

Scalability is another significant characteristic of HP Cluster Software. Organizations can easily add or remove nodes from the cluster without disrupting ongoing operations. This flexibility ensures that enterprises can adapt to changing workloads and resource demands efficiently, making it suitable for environments ranging from small businesses to large data centers.

Load balancing is a key technology employed by HP Cluster Software. It intelligently distributes workloads across the available nodes, optimizing resource utilization and ensuring that no single server is overwhelmed. By balancing the load, organizations can achieve better performance and enhance the response times of applications, which are essential for user satisfaction.

HP Cluster Software supports various clustering topologies, including active-active and active-passive configurations. This versatility allows organizations to choose the architecture that best fits their operational requirements. Additionally, the software integrates seamlessly with various HP and third-party hardware and software solutions, thus providing a holistic environment for managing IT resources.

Moreover, HP Cluster Software offers centralized management tools that simplify cluster administration. Administrators can monitor cluster performance, manage workloads, and configure settings all from a single interface. This ease of use reduces the complexity often associated with managing large clusters and empowers IT teams to respond rapidly to issues.

In summary, HP Cluster Software is an essential tool for organizations looking to enhance their IT infrastructure's availability, reliability, and performance. With its failover capabilities, scalability options, load balancing technology, and centralized management features, it stands out as a comprehensive solution for modern computing challenges.
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