InfoScale™ 9.0 Cluster Server Administrator's Guide - Windows

Last Published:
Product(s): InfoScale & Storage Foundation (9.0)
Platform: Windows
  1. Section I. Clustering concepts and terminology
    1. Introducing Cluster Server
      1. About Cluster Server
        1.  
          How VCS detects failure
        2. How VCS ensures application availability
          1.  
            About switchover and failover
      2. About cluster control guidelines
        1.  
          Defined start, stop, and monitor procedures
        2.  
          Ability to restart the application in a known state
        3.  
          External data storage
        4.  
          Licensing and host name issues
      3. About the physical components of VCS
        1.  
          About VCS nodes
        2.  
          About shared storage
        3.  
          About networking
      4. Logical components of VCS
        1.  
          About resources and resource dependencies
        2.  
          Categories of resources
        3.  
          About resource types
        4.  
          About service groups
        5. Types of service groups
          1.  
            About failover service groups
          2.  
            About parallel service groups
          3.  
            About hybrid service groups
        6.  
          About the ClusterService group
        7.  
          About agents in VCS
        8.  
          About agent functions
        9. Agent classifications
          1.  
            About bundled agents
          2.  
            About enterprise agents
          3.  
            About custom agents
        10.  
          VCS agent framework
        11. About cluster control, communications, and membership
          1.  
            About the high availability daemon (HAD)
          2.  
            About Group Membership Services and Atomic Broadcast (GAB)
          3.  
            About Low Latency Transport (LLT)
        12. About security services
          1.  
            Digital certification structure
          2.  
            Components for secure communication
          3.  
            Restriction after failed user login attempts
        13.  
          Components for administering VCS
      5.  
        Putting the pieces together
    2. About cluster topologies
      1. Basic failover configurations
        1.  
          Asymmetric or active / passive configuration
        2.  
          Symmetric or active / active configuration
        3.  
          About N-to-1 configuration
      2. About advanced failover configurations
        1.  
          About the N + 1 configuration
        2.  
          About the N-to-N configuration
      3. Cluster topologies and storage configurations
        1.  
          About basic shared storage cluster
        2.  
          About campus, or metropolitan, shared storage cluster
        3.  
          About shared nothing clusters
        4.  
          About replicated data clusters
        5.  
          About global clusters
    3. VCS configuration concepts
      1.  
        About configuring VCS
      2.  
        VCS configuration language
      3. About the main.cf file
        1.  
          About the SystemList attribute
        2.  
          Initial configuration
        3.  
          Including multiple .cf files in main.cf
      4.  
        About the types.cf file
      5. About VCS attributes
        1.  
          About attribute data types
        2.  
          About attribute dimensions
        3.  
          About attributes and cluster objects
        4.  
          Attribute scope across systems: global and local attributes
        5.  
          About attribute life: temporary attributes
        6.  
          Size limitations for VCS objects
      6.  
        VCS keywords and reserved words
      7.  
        VCS environment variables
  2. Section II. Administration - Putting VCS to work
    1. About the VCS user privilege model
      1. About VCS user privileges and roles
        1.  
          VCS privilege levels
        2.  
          User roles in VCS
        3.  
          Hierarchy in VCS roles
        4.  
          User privileges for CLI commands
        5.  
          User privileges for cross-cluster operations
        6.  
          User privileges for clusters that run in secure mode
      2.  
        How administrators assign roles to users
      3.  
        User privileges for OS user groups for clusters running in secure mode
      4.  
        VCS privileges for users with multiple roles
      5. Restricted user privileges
        1.  
          Restricting user privileges
        2.  
          Limitations on restricting user privileges
    2. Getting started with VCS
      1. Configuring the cluster using the Cluster Configuration Wizard
        1.  
          Configuring notification
        2.  
          Configuring Wide-Area Connector process for global clusters
      2. About configuring a cluster from the command line
        1. About preparing for a silent configuration
          1.  
            About configuring a non-secure cluster
          2.  
            About configuring a secure cluster
          3.  
            About deleting a non-secure cluster
          4.  
            About deleting a secure cluster
          5.  
            About element attributes values
          6.  
            About sample XML configuration
        2.  
          Running the silent configuration utility
    3. Administering the cluster from the command line
      1. About administering VCS from the command line
        1.  
          Symbols used in the VCS command syntax
        2.  
          How VCS identifies the local system
        3.  
          About specifying values preceded by a dash (-)
        4.  
          About the -modify option
        5.  
          Encrypting VCS passwords
        6. Encrypting agent passwords
          1.  
            Generating a security key
          2.  
            Encrypting the agent password
          3.  
            Changing the security key
      2.  
        Starting VCS
      3. Stopping the VCS engine and related processes
        1.  
          About stopping VCS without the -force option
        2.  
          About stopping VCS with options other than the -force option
        3.  
          About controlling the hastop behavior by using the EngineShutdown attribute
        4.  
          Additional considerations for stopping VCS
      4. About managing VCS configuration files
        1.  
          About the hacf utility
        2.  
          About multiple versions of .cf files
        3.  
          Verifying a configuration
        4.  
          Scheduling automatic backups for VCS configuration files
        5.  
          Saving a configuration
        6.  
          Setting the configuration to read or write
        7.  
          Displaying configuration files in the correct format
      5. About managing VCS users from the command line
        1.  
          Adding a user
        2.  
          Assigning and removing user privileges
        3.  
          Modifying a user
        4.  
          Deleting a user
        5.  
          Displaying a user
      6. About querying VCS
        1.  
          Querying service groups
        2.  
          Querying resources
        3.  
          Querying resource types
        4.  
          Querying agents
        5.  
          Querying systems
        6.  
          Querying clusters
        7.  
          Querying status
        8.  
          Querying log data files (LDFs)
        9.  
          Using conditional statements to query VCS objects
      7. About administering service groups
        1.  
          Adding and deleting service groups
        2. Modifying service group attributes
          1.  
            Modifying the SystemList attribute
        3.  
          Bringing service groups online
        4.  
          Taking service groups offline
        5.  
          Switching service groups
        6.  
          Freezing and unfreezing service groups
        7.  
          Enabling and disabling priority based failover for a service group
        8.  
          Enabling and disabling service groups
        9.  
          Clearing faulted resources in a service group
        10.  
          Linking and unlinking service groups
      8.  
        Administering agents
      9. About administering resources
        1.  
          About adding resources
        2.  
          Adding resources
        3.  
          Deleting resources
        4.  
          Adding, deleting, and modifying resource attributes
        5.  
          Defining attributes as local
        6.  
          Linking and unlinking resources
        7.  
          Bringing resources online
        8.  
          Taking resources offline
        9.  
          Probing a resource
        10.  
          Clearing a resource
      10. About administering resource types
        1.  
          Adding, deleting, and modifying resource types
        2.  
          Overriding resource type static attributes
      11.  
        Administering systems
      12. About administering clusters
        1.  
          Retrieving version information
      13.  
        Using the -wait option in scripts that use VCS commands
      14.  
        About administering simulated clusters from the command line
    4. Configuring resources and applications in VCS
      1. About configuring resources and applications
        1.  
          Considerations for Windows Server systems
      2. About Virtual Business Services
        1.  
          Features of Virtual Business Services
        2.  
          Sample virtual business service configuration
      3. About Intelligent Resource Monitoring (IMF)
        1.  
          VCS changes to support IMF
        2.  
          VCS agents that support IMF
        3.  
          How IMF works
        4.  
          How to enable IMF
        5.  
          How to disable IMF
        6. Recommended settings
          1.  
            Modify the MountV resource attributes
          2.  
            Modify the attribute values for SQL Analysis Service and SQL Server Agent resources
          3.  
            Modify the NumThreads attribute for MountV and VMDg
      4. About fast failover
        1.  
          VCS changes for fast failover
        2.  
          Enabling fast failover for disk groups
      5. How VCS monitors storage components
        1.  
          Shared storage - if you use NetApp filers
        2.  
          Shared storage - if you use SFW to manage cluster dynamic disk groups
        3.  
          Shared storage - if you use Windows LDM to manage shared disks
        4.  
          Non-shared storage - if you use SFW to manage dynamic disk groups
        5.  
          Non-shared storage - if you use Windows LDM to manage local disks
        6.  
          Non-shared storage - if you use VMware storage
      6. About storage configuration
        1. About managing storage using Windows Logical Disk Manager
          1.  
            Reserving disks (if you use Windows LDM)
          2.  
            Creating volumes (if you use Windows LDM)
          3.  
            Mounting volumes (if you use Windows LDM)
          4.  
            Unassigning a drive letter
          5.  
            Releasing disks (if you use Windows LDM)
          6.  
            Configuration tasks
        2. About managing storage in a Network Appliance storage environment
          1.  
            Configuring Microsoft iSCSI Initiator
          2.  
            Connecting virtual disks to the cluster node
          3.  
            Disconnecting virtual disks from the cluster nodes
        3. About managing shared storage using Storage Foundation for Windows
          1.  
            Using SFW with VCS
          2.  
            Before you configure shared storage using SFW
          3.  
            Configuring shared storage
        4.  
          Managing storage
      7. About configuring network resources
        1. About configuring IP addresses on the systems
          1.  
            Before you configure IP addresses on the systems
          2.  
            Disabling DHCP
          3.  
            Configuring IP addresses on the systems
        2. About configuring virtual computer names
          1.  
            Before you configure virtual computer names
          2.  
            Configuring virtual computer names
      8. About configuring file shares
        1.  
          Before you configure a file share service group
        2.  
          Configuring file shares using the wizard
        3.  
          Modifying a file share service group using the wizard
        4.  
          Deleting a file share service group using the wizard
        5.  
          Creating non-scoped file shares configured with VCS
        6.  
          Making non-scoped file shares accessible while using virtual server name or IP address if NetBIOS and WINS are disabled
      9. About configuring IIS sites
        1.  
          Before you configure an IIS service group
        2.  
          Fixing the IPv6 address configuration for FTP sites
        3.  
          Installing IIS on Windows Server Core
        4.  
          Configuring an IIS service group using the wizard
        5.  
          Modifying an IIS service group using the wizard
        6.  
          Deleting an IIS service group using the wizard
      10. About configuring services
        1.  
          About configuring a service using the GenericService agent
        2. Before you configure a service using the GenericService agent
          1.  
            Changing a service startup type
          2.  
            Configuring a service to run in a user context
        3.  
          Configuring a service using the GenericService agent
        4.  
          About configuring a service using the ServiceMonitor agent
        5.  
          Before you configure a service using the ServiceMonitor agent
        6.  
          Configuring a service using the ServiceMonitor agent
      11. About configuring processes
        1.  
          Before you configure processes
        2.  
          Configuring processes using the Process agent
      12. About configuring Microsoft Message Queuing (MSMQ)
        1.  
          Before you configure the MSMQ service group
        2.  
          Configuring the MSMQ resource using the command-line utility
        3.  
          Configuring the MSMQ service group using the wizard
        4.  
          Modifying an MSMQ service group using the wizard
        5.  
          Configuring MSMQ agent to check port bindings more than once
        6.  
          Binding an MSMQ instance to the correct IP address
        7.  
          Checking whether MSMQ is listening for messages
      13. About configuring the infrastructure and support agents
        1.  
          About configuring notification
        2. Configuring registry replication
          1.  
            About registry hive abbreviations
          2.  
            About excluding keys
          3.  
            About ignoring subkeys
          4.  
            About additional considerations for using IgnoreSubKeys
        3.  
          Configuring a proxy resource
        4.  
          Configuring a phantom resource
        5.  
          Configuring file resources
        6.  
          Configuring a RemoteGroup resource
      14. About configuring applications using the Application Configuration Wizard
        1.  
          Before you configure service groups using the Application Configuration wizard
        2. Adding resources to a service group
          1.  
            Configuring a GenericService resource
          2.  
            Configuring processes
          3.  
            Configuring a ServiceMonitor resource
          4.  
            Configuring VCS components
        3.  
          Configuring service groups using the Application Configuration Wizard
        4.  
          Modifying an application service group
        5.  
          Deleting resources from a service group
        6.  
          Deleting an application service group
      15. About application monitoring on single-node clusters
        1.  
          Configuring application monitoring on a single-node cluster
        2.  
          Verifying whether application monitoring is enabled on the single-node cluster
        3.  
          Unconfiguring application monitoring on a single-node cluster
        4.  
          About reviewing and troubleshooting the configuration and monitoring activities
      16. Configuring the service group in a non-shared storage environment
        1.  
          Setting the timeout duration for which the VMNSDg agent waits for all the disks to arrive before importing the disk group
      17. About the VCS Application Manager utility
        1.  
          Managing applications in virtual server context
      18. About testing resource failover using virtual fire drills
        1.  
          About virtual fire drills
        2.  
          About infrastructure checks and fixes for supported agents
        3.  
          About running a virtual fire drill
    5. Modifying the cluster configuration
      1.  
        About modifying the cluster configuration
      2.  
        Adding nodes to a cluster
      3.  
        Removing nodes from a cluster
      4.  
        Reconfiguring a cluster
      5.  
        Configuring single sign-on for the cluster manually
      6. Configuring the ClusterService group
        1.  
          Configuring notification
        2.  
          Configuring the wide-area connector process for global clusters
      7.  
        Deleting a cluster configuration
  3. Section III. Administration - Beyond the basics
    1. Controlling VCS behavior
      1. VCS behavior on resource faults
        1.  
          Critical and non-critical resources
        2. VCS behavior diagrams
          1.  
            Example scenario 1: Resource with critical parent faults
          2.  
            Example scenario 2: Resource with non-critical parent faults
          3.  
            Example scenario 3: Resource with critical parent fails to come online
      2. About controlling VCS behavior at the service group level
        1.  
          About the AutoRestart attribute
        2.  
          About controlling failover on service group or system faults
        3.  
          About defining failover policies
        4.  
          About system zones
        5.  
          Load-based autostart
        6.  
          About freezing service groups
        7.  
          About controlling Clean behavior on resource faults
        8.  
          Clearing resources in the ADMIN_WAIT state
        9.  
          About controlling fault propagation
        10. Customized behavior diagrams
          1.  
            Example scenario: Resource with a critical parent and ManageFaults=NONE
          2.  
            Example scenario: Resource with a critical parent and FaultPropagation=0
        11. VCS behavior for resources that support the intentional offline functionality
          1.  
            About the IntentionalOffline attribute
          2.  
            About the ExternalStateChange attribute
      3. About controlling VCS behavior at the resource level
        1. Resource type attributes that control resource behavior
          1.  
            About the RestartLimit attribute
          2.  
            About the OnlineRetryLimit attribute
          3.  
            About the ConfInterval attribute
          4.  
            About the ToleranceLimit attribute
          5.  
            About the FaultOnMonitorTimeouts attribute
        2. How VCS handles resource faults
          1.  
            VCS behavior when an online resource faults
          2.  
            VCS behavior when a resource fails to come online
        3.  
          VCS behavior after a resource is declared faulted
        4. About disabling resources
          1.  
            When to disable a resource
          2.  
            Limitations of disabling resources
          3.  
            Additional considerations for disabling resources
          4.  
            How disabled resources affect group states
      4.  
        Changing agent file paths and binaries
      5. Service group workload management
        1.  
          About enabling service group workload management
        2. System capacity and service group load
          1.  
            Static load versus dynamic load
          2.  
            About overload warning
        3.  
          System limits and service group prerequisites
        4.  
          About capacity and limits
      6. Sample configurations depicting workload management
        1.  
          System and Service group definitions
        2. Sample configuration: Basic four-node cluster
          1.  
            About AutoStart operation
          2.  
            About the failure scenario
          3.  
            About the cascading failure scenario
        3. Sample configuration: Complex four-node cluster
          1.  
            About the AutoStart operation
          2.  
            About the normal operation
          3.  
            About the failure scenario
          4.  
            About the cascading failure scenario
        4. Sample configuration: Server consolidation
          1.  
            About the AutoStart operation
          2.  
            About the normal operation
          3.  
            About the failure scenario
          4.  
            About the cascading failure scenario
    2. The role of service group dependencies
      1. About service group dependencies
        1. About dependency links
          1.  
            Dependency categories
          2.  
            Dependency location
          3.  
            Dependency rigidity
        2.  
          About dependency limitations
      2. Service group dependency configurations
        1. About failover parent / failover child
          1.  
            About failover parent / parallel child
          2.  
            About parallel parent / failover child
          3.  
            About parallel parent / parallel child
      3.  
        Frequently asked questions about group dependencies
      4.  
        About linking service groups
      5. VCS behavior with service group dependencies
        1.  
          Online operations in group dependencies
        2.  
          Offline operations in group dependencies
        3.  
          Switch operations in group dependencies
    3. VCS event notification
      1. About VCS event notification
        1.  
          Event messages and severity levels
        2.  
          About persistent and replicated message queue
        3.  
          How HAD deletes messages
      2. Components of VCS event notification
        1. About the notifier process
          1.  
            Example of notifier command
        2. About the hanotify utility
          1.  
            Example of hanotify command
      3. About VCS events and traps
        1.  
          Events and traps for clusters
        2.  
          Events and traps for agents
        3.  
          Events and traps for resources
        4.  
          Events and traps for systems
        5.  
          Events and traps for service groups
        6.  
          SNMP-specific files
        7. Trap variables in VCS MIB
          1.  
            About severityId
          2.  
            EntityType and entitySubType
          3.  
            About entityState
      4. About monitoring aggregate events
        1.  
          How to detect service group failover
        2.  
          How to detect service group switch
      5.  
        About configuring notification
    4. VCS event triggers
      1.  
        About VCS event triggers
      2.  
        Using event triggers
      3. List of event triggers
        1.  
          About the dumptunables trigger
        2.  
          About the injeopardy event trigger
        3.  
          About the loadwarning event trigger
        4.  
          About the nofailover event trigger
        5.  
          About the postoffline event trigger
        6.  
          About the postonline event trigger
        7.  
          About the preonline event trigger
        8.  
          About the resadminwait event trigger
        9.  
          About the resfault event trigger
        10.  
          About the resnotoff event trigger
        11.  
          About the resrestart event trigger
        12.  
          About the resstatechange event trigger
        13.  
          About the sysoffline event trigger
        14.  
          About the unable_to_restart_agent event trigger
        15.  
          About the unable_to_restart_had event trigger
        16.  
          About the violation event trigger
  4. Section IV. Cluster configurations for disaster recovery
    1. Connecting clusters–Creating global clusters
      1.  
        How VCS global clusters work
      2. VCS global clusters: The building blocks
        1.  
          Visualization of remote cluster objects
        2.  
          About global service groups
        3. About global cluster management
          1.  
            About the wide-area connector process
          2.  
            About the wide-area heartbeat agent
        4. About serialization - The Authority attribute
          1.  
            About the Authority and AutoStart attributes
        5.  
          About resiliency and "Right of way"
        6.  
          VCS agents to manage wide-area failover
        7.  
          About the Steward process: Split-brain in two-cluster global clusters
        8.  
          Secure communication in global clusters
      3. Prerequisites for global clusters
        1.  
          Prerequisites for cluster setup
        2.  
          Prerequisites for application setup
        3.  
          Prerequisites for wide-area heartbeats
        4.  
          Prerequisites for ClusterService group
        5.  
          Prerequisites for replication setup
      4. Setting up a global cluster
        1.  
          Preparing the application for the global environment
        2.  
          Configuring the ClusterService group
        3. Configuring replication resources in VCS
          1.  
            About the prerequisites for configuring replication resources in VCS
        4.  
          Linking the application and replication service groups
        5.  
          Configuring the second cluster
        6.  
          Linking clusters
        7.  
          Configuring the Steward process (optional)
        8.  
          Stopping the Steward process
        9.  
          Configuring the global service group
      5. About IPv6 support with global clusters
        1.  
          Prerequisites for configuring a global cluster to support IPv6
        2.  
          Migrating an InfoScale Availability cluster from IPv4 to IPv6 when Virtual IP (ClusterAddress) is configured
        3.  
          Migrating an InfoScale Availability cluster to IPv6 in a GCO deployment
      6. About cluster faults
        1.  
          About the type of failure
        2.  
          Switching the service group back to the primary
      7. About setting up a disaster recovery fire drill
        1. About creating and configuring the fire drill service group manually
          1.  
            Creating the fire drill service group
          2.  
            Linking the fire drill and replication service groups
          3.  
            Adding resources to the fire drill service group
          4.  
            Configuring the fire drill service group
          5.  
            Enabling the FireDrill attribute
      8.  
        Multi-tiered application support using the RemoteGroup agent in a global environment
      9. Test scenario for a multi-tiered environment
        1.  
          About the main.cf file for cluster 1
        2.  
          About the main.cf file for cluster 2
        3.  
          About the main.cf file for cluster 3
        4.  
          About the main.cf file for cluster 4
    2. Administering global clusters from Cluster Manager (Java console)
      1.  
        About global clusters
      2.  
        Adding a remote cluster
      3.  
        Deleting a remote cluster
      4. Administering global service groups
        1.  
          Converting local and global groups
        2.  
          Bringing a service group online in a remote cluster
        3.  
          Taking a service group offline in a remote cluster
        4.  
          Switching a service group to a remote cluster
      5. Administering global heartbeats
        1.  
          Adding a global heartbeat
        2.  
          Modifying a global heartbeat
        3.  
          Deleting a global heartbeat
    3. Administering global clusters from the command line
      1.  
        About administering global clusters from the command line
      2. About global querying in a global cluster setup
        1.  
          Querying global cluster service groups
        2.  
          Querying resources across clusters
        3.  
          Querying systems
        4.  
          Querying clusters
        5.  
          Querying status
        6.  
          Querying heartbeats
      3.  
        Administering global service groups in a global cluster setup
      4.  
        Administering resources in a global cluster setup
      5. Administering clusters in global cluster setup
        1.  
          Managing cluster alerts in a global cluster setup
        2.  
          Changing the cluster name in a global cluster setup
      6.  
        Administering heartbeats in a global cluster setup
    4. Setting up replicated data clusters
      1.  
        About replicated data clusters
      2.  
        How VCS replicated data clusters work
      3.  
        About setting up a replicated data cluster configuration
  5. Section V. Troubleshooting and performance
    1. VCS performance considerations
      1. How cluster components affect performance
        1.  
          How kernel components (GAB and LLT) affect performance
        2.  
          How the VCS engine (HAD) affects performance
        3. How agents affect performance
          1.  
            Monitoring resource type and agent configuration
        4.  
          How the VCS graphical user interfaces affect performance
        5.  
          If the network adapters cannot ping each other, the cluster nodes may not get GAB membership
      2. How cluster operations affect performance
        1.  
          VCS performance consideration when booting a cluster system
        2.  
          VCS performance consideration when a resource comes online
        3.  
          VCS performance consideration when a resource goes offline
        4.  
          VCS performance consideration when a service group comes online
        5.  
          VCS performance consideration when a service group goes offline
        6.  
          VCS performance consideration when a resource fails
        7.  
          VCS performance consideration when a system fails
        8.  
          VCS performance consideration when a network link fails
        9. VCS performance consideration when a system panics
          1.  
            About GAB client process failure
          2.  
            About GAB client registration monitoring
          3.  
            About network failure and GAB IOFENCE message
          4.  
            About quick reopen
        10.  
          VCS performance consideration when a service group switches over
        11.  
          VCS performance consideration when a service group fails over
      3.  
        Monitoring CPU usage
      4. VCS agent statistics
        1.  
          Tracking monitor cycle times
        2.  
          VCS attributes enabling agent statistics
      5.  
        About VCS performance with non-HA products
      6.  
        About VCS performance with SFW
    2. Troubleshooting and recovery for VCS
      1. VCS message logging
        1.  
          VCW logs
        2.  
          VCWsilent logs
        3.  
          Solutions wizard logs
        4.  
          Message catalogs
      2. Handling network failure
        1.  
          Disabling failover
        2. Example of how VCS handles network failure
          1.  
            Jeopardy scenario: link failure
          2.  
            Jeopardy scenario: link and node failure
          3.  
            Jeopardy scenario: failure of all links
        3.  
          Network partitioning
        4.  
          When VCS shuts down a system
        5.  
          Pre-existing network partitions
        6.  
          Seeding of VCS clusters
        7.  
          Reconnecting the private network
      3. Troubleshooting VCS startup
        1. Low Latency Transport (LLT)
          1.  
            Common LLT directives
        2.  
          Group Membership Atomic Broadcast (GAB)
        3. Verifying LLT, GAB, and cluster operation
          1.  
            Verifying LLT
          2.  
            Setting the checksum option
          3.  
            Verifying GAB
          4.  
            Verifying HAD
          5.  
            Verifying the cluster
        4. VCS startup errors
          1.  
            Seeding the cluster
        5.  
          Cluster ID is not unique over a network
      4.  
        Troubleshooting secure clusters
      5. Troubleshooting service groups
        1.  
          ClusterService group configuration
      6.  
        Troubleshooting resources
      7.  
        Troubleshooting notification
      8. Troubleshooting and recovery for global clusters
        1.  
          Disaster declaration
        2.  
          Lost heartbeats and the inquiry mechanism
        3. VCS alerts
          1.  
            Types of alerts
          2.  
            Managing alerts
          3.  
            Actions associated with alerts
          4.  
            Negating events
      9.  
        Troubleshooting the steward process
      10. VCS utilities
        1. The getcomms utility
          1.  
            getcomms options
          2.  
            Log location
        2. The hagetcf utility
          1.  
            Log location
          2.  
            Options for the hagetcf utility
        3.  
          The NICTest utility
        4.  
          The VCSRegUtil utility
        5. The havol utility
          1.  
            Using the -getdrive option
          2.  
            Using the -scsitest option
          3.  
            Retrieving the disk number
          4.  
            The -scsitest command options
        6.  
          The vmgetdrive utility
        7. Configuring the VCS Helper service manually
          1.  
            Command syntax
          2.  
            Command options
  6. Section VI. Appendixes
    1. Appendix A. VCS user privileges—administration matrices
      1.  
        About administration matrices
      2. Administration matrices
        1.  
          Agent Operations (haagent)
        2.  
          Attribute Operations (haattr)
        3.  
          Cluster Operations (haclus, haconf)
        4.  
          Service group operations (hagrp)
        5.  
          Heartbeat operations (hahb)
        6.  
          Log operations (halog)
        7.  
          Resource operations (hares)
        8.  
          System operations (hasys)
        9.  
          Resource type operations (hatype)
        10.  
          User operations (hauser)
    2. Appendix B. Cluster and system states
      1. Remote cluster states
        1.  
          Examples of cluster state transitions
      2. System states
        1.  
          Examples of system state transitions
    3. Appendix C. VCS attributes
      1.  
        About attributes and their definitions
      2.  
        Resource attributes
      3.  
        Resource type attributes
      4.  
        Service group attributes
      5.  
        System attributes
      6.  
        Cluster attributes
      7.  
        Heartbeat attributes (for global clusters)
      8.  
        Remote cluster attributes
    4. Appendix D. Configuring LLT over UDP
      1.  
        About configuring LLT over UDP
      2.  
        When to use LLT over UDP
      3. LLT over UDP configuration
        1.  
          The link command in the llttab file
        2.  
          The set-addr command in the llttab file
        3.  
          Selecting UDP ports
      4.  
        Sample configuration: Direct-attached links
      5.  
        Sample configuration: Links crossing IP routers
      6. Issues and limitations
        1.  
          VCW does not support configuring broadcasting for UDP
        2.  
          If the network adapters are unable to ping each other, the cluster nodes may not get GAB membership
    5. Appendix E. Handling concurrency violation in any-to-any configurations
      1.  
        About handling concurrency violation
      2.  
        Concurrency violation scenario
      3.  
        About the vcsgensvc.vbs script
      4. Sample configuration to handle concurrency violation
        1.  
          Notes for using scripts with the Process agent
    6. Appendix F. Accessibility and VCS
      1.  
        About accessibility in VCS
      2. Navigation and keyboard shortcuts
        1.  
          Navigation in the Java Console
        2.  
          Navigation in the Web console
      3.  
        Support for accessibility settings
      4.  
        Support for assistive technologies
    7. Appendix G. Executive Order logging
      1.  
        Executive Order logging
      2.  
        Log formatting
      3.  
        Enabling cluster server logs
      4.  
        Log forwarding

Symmetric or active / active configuration

In a symmetric configuration, each server is configured to run a specific application or service and provide redundancy for its peer. In this example, each server runs one application service group. When a failure occurs, the surviving server hosts both application groups.

Figure: Symmetric failover shows failover within a symmetric cluster configuration.

Figure: Symmetric failover

Symmetric failover

Symmetric configurations appear more efficient in terms of hardware utilization. In the asymmetric example, the redundant server requires only as much processor power as its peer. On failover, performance remains the same. In the symmetric example, the redundant server requires adequate processor power to run the existing application and the new application it takes over.

Further issues can arise in symmetric configurations when multiple applications that run on the same system do not co-exist properly. Some applications work well with multiple copies started on the same system, but others fail. Issues also can arise when two applications with different I/O and memory requirements run on the same system.