InfoScale™ 9.0 Disaster Recovery Implementation Guide - Linux

Last Published:
Product(s): InfoScale & Storage Foundation (9.0)
Platform: Linux
  1. Section I. Introducing Storage Foundation and High Availability Solutions for disaster recovery
    1. About supported disaster recovery scenarios
      1.  
        About disaster recovery scenarios
      2. About campus cluster configuration
        1.  
          VCS campus cluster requirements
        2.  
          How VCS campus clusters work
        3.  
          Typical VCS campus cluster setup
      3. About replicated data clusters
        1.  
          How VCS replicated data clusters work
      4. About global clusters
        1.  
          How VCS global clusters work
        2.  
          User privileges for cross-cluster operations
        3. 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
            3.  
              Sample configuration for 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
      5.  
        Disaster recovery feature support for components in the Veritas InfoScale product suite
      6.  
        Virtualization support for InfoScale 9.0 products in replicated environments
    2. Planning for disaster recovery
      1. Planning for cluster configurations
        1.  
          Planning a campus cluster setup
        2.  
          Planning a replicated data cluster setup
        3.  
          Planning a global cluster setup
      2. Planning for data replication
        1.  
          Data replication options
        2.  
          Data replication considerations
  2. Section II. Implementing campus clusters
    1. Setting up campus clusters for VCS and SFHA
      1. About setting up a campus cluster configuration
        1.  
          Preparing to set up a campus cluster configuration
        2.  
          Configuring I/O fencing to prevent data corruption
        3.  
          Configuring VxVM disk groups for campus cluster configuration
        4.  
          Configuring VCS service group for campus clusters
        5.  
          Setting up campus clusters for VxVM and VCS using Veritas InfoScale Operations Manager
      2.  
        Fire drill in campus clusters
      3.  
        About the DiskGroupSnap agent
      4. About running a fire drill in a campus cluster
        1.  
          Configuring the fire drill service group
        2.  
          Running a successful fire drill in a campus cluster
    2. Setting up campus clusters for SFCFSHA, SFRAC
      1.  
        About setting up a campus cluster for disaster recovery for SFCFSHA or SF Oracle RAC
      2.  
        Preparing to set up a campus cluster in a parallel cluster database environment
      3.  
        Configuring I/O fencing to prevent data corruption
      4.  
        Configuring VxVM disk groups for a campus cluster in a parallel cluster database environment
      5.  
        Configuring VCS service groups for a campus cluster for SFCFSHA and SF Oracle RAC
      6.  
        Tuning guidelines for parallel campus clusters
      7.  
        Best practices for a parallel campus cluster
  3. Section III. Implementing replicated data clusters
    1. Configuring a replicated data cluster using VVR
      1. About setting up a replicated data cluster configuration
        1.  
          About typical replicated data cluster configuration
        2.  
          About setting up replication
        3.  
          Configuring the service groups
        4.  
          Configuring the service group dependencies
      2. About migrating a service group
        1.  
          Switching the service group
      3.  
        Fire drill in replicated data clusters
    2. Configuring a replicated data cluster using third-party replication
      1.  
        About setting up a replicated data cluster configuration using third-party replication
      2.  
        About typical replicated data cluster configuration using third-party replication
      3.  
        About setting up third-party replication
      4.  
        Configuring the service groups for third-party replication
      5.  
        Fire drill in replicated data clusters using third-party replication
  4. Section IV. Implementing global clusters
    1. Configuring global clusters for VCS and SFHA
      1.  
        Installing and Configuring Cluster Server
      2. Setting up VVR replication
        1.  
          About configuring VVR replication
        2.  
          Best practices for setting up replication
        3. Creating a Replicated Data Set
          1. Creating a Primary RVG of an RDS
            1.  
              Prerequisites for creating a Primary RVG of an RDS
            2.  
              Example - Creating a Primary RVG containing a data volume
            3.  
              Example - Creating a Primary RVG containing a volume set
          2. Adding a Secondary to an RDS
            1.  
              Best practices for adding a Secondary to an RDS
            2.  
              Prerequisites for adding a Secondary to an RDS
          3. Changing the replication settings for a Secondary
            1. Setting the mode of replication for a Secondary
              1.  
                Example - Setting the mode of replication to asynchronous for an RDS
              2.  
                Example - Setting the mode of replication to synchronous for an RDS
            2.  
              Setting the latency protection for a Secondary
            3.  
              Setting the SRL overflow protection for a Secondary
            4.  
              Setting the network transport protocol for a Secondary
            5. Setting the packet size for a Secondary
              1.  
                Example - Setting the packet size between the Primary and Secondary
            6. Setting the bandwidth limit for a Secondary
              1.  
                Example: Limiting network bandwidth between the Primary and the Secondary
              2.  
                Example: Disabling Bandwidth Throttling between the Primary and the Secondary
              3.  
                Example: Limiting network bandwidth used by VVR when using full synchronization
        4. Synchronizing the Secondary and starting replication
          1. Methods to synchronize the Secondary
            1.  
              Using the network to synchronize the Secondary
            2.  
              Using block-level tape backup to synchronize the Secondary
            3.  
              Moving disks physically to synchronize the Secondary
          2. Using the automatic synchronization feature
            1.  
              Notes on using automatic synchronization
          3.  
            Example for setting up replication using automatic synchronization
          4.  
            About SmartMove for VVR
          5.  
            About thin storage reclamation and VVR
          6.  
            Determining if a thin reclamation array needs reclamation
        5. Starting replication when the data volumes are zero initialized
          1.  
            Example: Starting replication when the data volumes are zero initialized
      3.  
        Setting up third-party replication
      4. Configuring clusters for global cluster setup
        1.  
          Configuring global cluster components at the primary site
        2.  
          Installing and configuring VCS at the secondary site
        3.  
          Securing communication between the wide-area connectors
        4.  
          Configuring remote cluster objects
        5.  
          Configuring additional heartbeat links (optional)
        6.  
          Configuring the Steward process (optional)
      5. Configuring service groups for global cluster setup
        1.  
          Configuring VCS service group for VVR-based replication
        2.  
          Configuring a service group as a global service group
      6.  
        Fire drill in global clusters
    2. Configuring a global cluster with Storage Foundation Cluster File System High Availability, Storage Foundation for Oracle RAC, or Storage Foundation for Sybase CE
      1.  
        About global clusters
      2.  
        About replication for parallel global clusters using Storage Foundation and High Availability (SFHA) Solutions
      3.  
        About setting up a global cluster environment for parallel clusters
      4.  
        Configuring the primary site
      5. Configuring the secondary site
        1.  
          Configuring the Sybase ASE CE cluster on the secondary site
      6.  
        Setting up replication between parallel global cluster sites
      7.  
        Testing a parallel global cluster configuration
    3. Configuring global clusters with VVR and Storage Foundation Cluster File System High Availability, Storage Foundation for Oracle RAC, or Storage Foundation for Sybase CE
      1.  
        About configuring a parallel global cluster using Volume Replicator (VVR) for replication
      2. Setting up replication on the primary site using VVR
        1.  
          Creating the data and SRL volumes on the primary site
        2.  
          Setting up the Replicated Volume Group on the primary site
      3. Setting up replication on the secondary site using VVR
        1.  
          Creating the data and SRL volumes on the secondary site
        2.  
          Editing the /etc/vx/vras/.rdg files
        3.  
          Setting up IP addresses for RLINKs on each cluster
        4.  
          Setting up the disk group on secondary site for replication
      4.  
        Starting replication of the primary site database volume to the secondary site using VVR
      5. Configuring Cluster Server to replicate the database volume using VVR
        1.  
          Modifying the Cluster Server (VCS) configuration on the primary site
        2.  
          Modifying the VCS configuration on the secondary site
        3.  
          Configuring the Sybase ASE CE cluster on the secondary site
      6.  
        Replication use cases for global parallel clusters
  5. Section V. Reference
    1. Appendix A. Sample configuration files
      1. Sample Storage Foundation for Oracle RAC configuration files
        1.  
          sfrac02_main.cf file
        2.  
          sfrac07_main.cf and sfrac08_main.cf files
        3.  
          sfrac09_main.cf and sfrac10_main.cf files
        4.  
          sfrac11_main.cf file
        5.  
          sfrac12_main.cf and sfrac13_main.cf files
        6.  
          Sample fire drill service group configuration
      2. About sample main.cf files for Storage Foundation (SF) for Oracle RAC
        1.  
          Sample main.cf for Oracle 10g for CVM/VVR primary site
        2.  
          Sample main.cf for Oracle 10g for CVM/VVR secondary site
      3. About sample main.cf files for Storage Foundation (SF) for Sybase ASE CE
        1.  
          Sample main.cf for a basic Sybase ASE CE cluster configuration under VCS control with shared mount point on CFS for Sybase binary installation
        2.  
          Sample main.cf for a basic Sybase ASE CE cluster configuration with local mount point on VxFS for Sybase binary installation
        3.  
          Sample main.cf for a primary CVM VVR site
        4.  
          Sample main.cf for a secondary CVM VVR site

About the Steward process: Split-brain in two-cluster global clusters

Failure of all heartbeats between any two clusters in a global cluster indicates one of the following:

  • The remote cluster is faulted.

  • All communication links between the two clusters are broken.

In global clusters with three or more clusters, VCS queries the connected clusters to confirm that the remote cluster is truly down. This mechanism is called inquiry.

In a two-cluster setup, VCS uses the Steward process to minimize chances of a wide-area split-brain. The process runs as a standalone binary on a system outside of the global cluster configuration.

To configure redundancy for the Steward process, you can configure Steward in one of the following ways:

  • Configure high availability of a single Steward process:

    You can configure the Steward process in a two-node cluster. In case of a failure, the Steward process fails over to the other node in the cluster.

  • Configure multiple Stewards:

    You can configure multiple Stewards. Each Steward can be configured at a different site. If the communication links between one of the Stewards and one of the clusters are lost, the Steward process at the other site can respond to the inquiry.

Figure: Steward process: Split-brain in two-cluster global clusters depicts the Steward process to minimize chances of a split brain within a two-cluster setup.

Figure: Steward process: Split-brain in two-cluster global clusters

Steward process: Split-brain in two-cluster global clusters

When all communication links between any two clusters are lost, each cluster contacts the Steward with an inquiry message. The Steward sends an ICMP ping to the cluster in question and responds with a negative inquiry if the cluster is running or with positive inquiry if the cluster is down. In case of multiple stewards, the cluster sends the inquiry to all the Stewards simultaneously. If at least one Steward responds with a negative inquiry, VCS assumes that the other cluster is running and does not need any corrective action.

The Steward can also be used in configurations with more than two clusters. VCS provides the option of securing communication between the Steward process and the wide-area connectors.

In non-secure configurations, you can configure the steward process on a platform that is different to that of the global cluster nodes. Secure configurations have not been tested for running the steward process on a different platform.

For example, you can run the steward process on a Windows system for a global cluster running on Linux systems. However, the VCS release for Linux contains the steward binary for Linux only. You must copy the steward binary for Windows from the VCS installation directory on a Windows cluster, typically C:\Program Files\VERITAS\Cluster Server.

A Steward is effective only if there are independent paths from each cluster to the host that runs the Steward. If there is only one path between the two clusters, you must prevent split-brain by confirming manually via telephone or some messaging system with administrators at the remote site if a failure has occurred. By default, VCS global clusters fail over an application across cluster boundaries with administrator confirmation. You can configure automatic failover by setting the ClusterFailOverPolicy attribute to Auto.

For more information on configuring the Steward process, see the Cluster Server Administrator's Guide.

The default port for the steward is 14156.

More Information

Secure communication in global clusters