Clearing preexisting split-brain condition | Fencing startup reports preexisting split-brain | Troubleshooting I/O fencing | Troubleshooting SF Oracle RAC | Section II. Performance and troubleshooting | Storage Foundation for Oracle® RAC 7.3.1 Administrator's Guide - Linux | Veritas™

Storage Foundation for Oracle® RAC 7.3.1 Administrator's Guide - Linux

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Product(s): InfoScale & Storage Foundation (7.3.1)
  1. Section I. SF Oracle RAC concepts and administration
    1. Overview of Storage Foundation for Oracle RAC
      1. About Storage Foundation for Oracle RAC
        1.  
          Benefits of SF Oracle RAC
      2.  
        How SF Oracle RAC works (high-level perspective)
      3. Component products and processes of SF Oracle RAC
        1. Communication infrastructure
          1.  
            Data flow
          2.  
            Communication requirements
        2. Cluster interconnect communication channel
          1. About Low Latency Transport (LLT)
            1.  
              How LLT supports RDMA capability for faster interconnects between applications
          2.  
            Group Membership Services/Atomic Broadcast
        3.  
          Low-level communication: port relationship between GAB and processes
        4. Cluster Volume Manager (CVM)
          1.  
            CVM architecture
          2.  
            CVM communication
          3.  
            CVM recovery
          4.  
            Configuration differences with VxVM
          5. About Flexible Storage Sharing
            1.  
              Flexible Storage Sharing use cases
            2.  
              Limitations of Flexible Storage Sharing
        5. Cluster File System (CFS)
          1.  
            CFS architecture
          2.  
            CFS communication
          3.  
            CFS file system benefits
          4.  
            CFS configuration differences
          5.  
            CFS recovery
          6.  
            Comparing raw volumes and CFS for data files
        6. Cluster Server (VCS)
          1.  
            VCS architecture
          2. VCS communication
            1.  
              About the IMF notification module
          3. About resource monitoring
            1.  
              How intelligent resource monitoring works
          4.  
            Cluster configuration files
        7.  
          About I/O fencing
        8. Oracle RAC components
          1. Oracle Clusterware/Grid Infrastructure
            1.  
              Co-existence with VCS
          2.  
            Oracle Cluster Registry
          3. Application resources
            1.  
              Resource profiles
            2.  
              Oracle Clusterware/Grid Infrastructure node applications
            3.  
              Voting disk
        9. Oracle Disk Manager
          1.  
            ODM architecture
          2.  
            Veritas ODM performance enhancements
          3.  
            ODM communication
        10. RAC extensions
          1.  
            Veritas Cluster Server membership manager
          2.  
            Oracle and cache fusion traffic
      4.  
        Periodic health evaluation of SF Oracle RAC clusters
      5. About Virtual Business Services
        1.  
          Features of Virtual Business Services
        2.  
          Sample virtual business service configuration
      6.  
        About Veritas InfoScale Operations Manager
      7.  
        About Veritas Services and Operations Readiness Tools (SORT)
    2. Administering SF Oracle RAC and its components
      1. Administering SF Oracle RAC
        1.  
          Setting the environment variables for SF Oracle RAC
        2. Starting or stopping SF Oracle RAC on each node
          1.  
            Starting SF Oracle RAC using the script-based installer
          2.  
            Starting SF Oracle RAC manually on each node
          3.  
            Stopping SF Oracle RAC using the script-based installer
          4.  
            Stopping SF Oracle RAC manually on each node
        3.  
          Applying Oracle patches on SF Oracle RAC nodes
        4.  
          Migrating Pluggable Databases (PDB) between Container Databases (CDB)
        5.  
          Installing Veritas Volume Manager, Veritas File System, or ODM patches on SF Oracle RAC nodes
        6.  
          Applying operating system updates on SF Oracle RAC nodes
        7.  
          Adding storage to an SF Oracle RAC cluster
        8.  
          Recovering from storage failure
        9.  
          Backing up and restoring Oracle database using Veritas NetBackup
        10.  
          Enhancing the performance of SF Oracle RAC clusters
        11.  
          Administering SmartIO
        12.  
          Creating snapshots for offhost processing
        13.  
          Managing database storage efficiently using SmartTier
        14.  
          Optimizing database storage using Thin Provisioning and SmartMove
        15.  
          Scheduling periodic health checks for your SF Oracle RAC cluster
        16.  
          Using environment variables to start and stop VCSMM modules
        17.  
          Verifying the nodes in an SF Oracle RAC cluster
      2. Administering VCS
        1.  
          About managing VCS modules
        2.  
          Viewing available Veritas device drivers
        3.  
          Starting and stopping VCS
        4.  
          Environment variables to start and stop VCS modules
        5.  
          Adding and removing LLT links
        6.  
          Configuring aggregated interfaces under LLT
        7.  
          Displaying the cluster details and LLT version for LLT links
        8.  
          Configuring destination-based load balancing for LLT
        9.  
          Enabling and disabling intelligent resource monitoring for agents manually
        10.  
          Administering the AMF kernel driver
      3. Administering I/O fencing
        1.  
          About administering I/O fencing
        2. About the vxfentsthdw utility
          1.  
            General guidelines for using the vxfentsthdw utility
          2.  
            About the vxfentsthdw command options
          3. Testing the coordinator disk group using the -c option of vxfentsthdw
            1.  
              Removing and replacing a failed disk
          4.  
            Performing non-destructive testing on the disks using the -r option
          5.  
            Testing the shared disks using the vxfentsthdw -m option
          6.  
            Testing the shared disks listed in a file using the vxfentsthdw -f option
          7.  
            Testing all the disks in a disk group using the vxfentsthdw -g option
          8.  
            Testing a disk with existing keys
        3. About the vxfenadm utility
          1.  
            About the I/O fencing registration key format
          2.  
            Displaying the I/O fencing registration keys
          3.  
            Verifying that the nodes see the same disk
        4. About the vxfenclearpre utility
          1.  
            Removing preexisting keys
        5. About the vxfenswap utility
          1.  
            Replacing I/O fencing coordinator disks when the cluster is online
          2.  
            Replacing the coordinator disk group in a cluster that is online
          3.  
            Adding disks from a recovered site to the coordinator disk group
          4.  
            Refreshing lost keys on coordinator disks
        6.  
          Enabling or disabling the preferred fencing policy
        7.  
          About I/O fencing log files
        8.  
          Migrating from disk-based fencing to server-based fencing using the installer
        9.  
          Migrating from server-based fencing to disk-based fencing using the installer
      4. Administering the CP server
        1.  
          Refreshing registration keys on the coordination points for server-based fencing
        2.  
          Replacing coordination points for server-based fencing in an online cluster
        3.  
          Migrating from non-secure to secure setup for CP server and SF Oracle RAC cluster communication
      5. Administering CFS
        1.  
          Adding CFS file systems to a VCS configuration
        2.  
          Resizing CFS file systems
        3.  
          Verifying the status of CFS file system nodes and their mount points
      6. Administering CVM
        1.  
          Listing all the CVM shared disks
        2.  
          Establishing CVM cluster membership manually
        3. Changing the CVM master manually
          1.  
            Considerations for changing the master manually
          2.  
            Errors during CVM master switching
        4.  
          Importing a shared disk group manually
        5.  
          Deporting a shared disk group manually
        6.  
          Starting shared volumes manually
        7.  
          Verifying if CVM is running in an SF Oracle RAC cluster
        8.  
          Verifying CVM membership state
        9.  
          Verifying the state of CVM shared disk groups
        10.  
          Verifying the activation mode
      7. Administering Flexible Storage Sharing
        1.  
          About Flexible Storage Sharing disk support
        2.  
          About the volume layout for Flexible Storage Sharing disk groups
        3.  
          Setting the host prefix
        4.  
          Exporting a disk for Flexible Storage Sharing
        5.  
          Setting the Flexible Storage Sharing attribute on a disk group
        6.  
          Using the host disk class and allocating storage
        7.  
          Administering mirrored volumes using vxassist
        8.  
          Displaying exported disks and network shared disk groups
        9.  
          Tuning LLT for memory and performance in FSS environments
        10. Backing up and restoring disk group configuration data
          1.  
            Backing up and restoring Flexible Storage Sharing disk group configuration data
      8. Administering SF Oracle RAC global clusters
        1.  
          About setting up a disaster recovery fire drill
        2. About configuring the fire drill service group using the Fire Drill Setup wizard
          1.  
            Running the fire drill setup wizard
          2.  
            About configuring local attributes in the fire drill service group
        3.  
          Verifying a successful fire drill
        4.  
          Scheduling a fire drill
        5.  
          Sample fire drill service group configuration
  2. Section II. Performance and troubleshooting
    1. Troubleshooting SF Oracle RAC
      1. About troubleshooting SF Oracle RAC
        1. Gathering information from an SF Oracle RAC cluster for support analysis
          1.  
            Gathering configuration information using SORT Data Collector
          2.  
            Gathering SF Oracle RAC information for support analysis
          3.  
            Gathering VCS information for support analysis
          4.  
            Gathering LLT and GAB information for support analysis
          5.  
            Gathering IMF information for support analysis
        2. SF Oracle RAC log files
          1.  
            Collecting important CVM logs
        3.  
          About SF Oracle RAC kernel and driver messages
        4. VCS message logging
          1.  
            GAB message logging
          2.  
            About debug log tags usage
          3.  
            Enabling debug logs for agents
          4.  
            Enabling debug logs for the VCS engine
          5.  
            Enabling debug logs for IMF
          6.  
            Message catalogs
      2.  
        Restarting the installer after a failed network connection
      3.  
        Installer cannot create UUID for the cluster
      4.  
        Troubleshooting SF Oracle RAC pre-installation check failures
      5.  
        Troubleshooting LLT health check warning messages
      6. Troubleshooting I/O fencing
        1.  
          SCSI reservation errors during bootup
        2.  
          The vxfentsthdw utility fails when SCSI TEST UNIT READY command fails
        3.  
          Node is unable to join cluster while another node is being ejected
        4.  
          System panics to prevent potential data corruption
        5.  
          Cluster ID on the I/O fencing key of coordinator disk does not match the local cluster's ID
        6. Fencing startup reports preexisting split-brain
          1.  
            Clearing preexisting split-brain condition
        7.  
          Registered keys are lost on the coordinator disks
        8.  
          Replacing defective disks when the cluster is offline
        9.  
          Troubleshooting I/O fencing health check warning messages
        10. Troubleshooting CP server
          1.  
            Troubleshooting issues related to the CP server service group
          2.  
            Checking the connectivity of CP server
        11. Troubleshooting server-based fencing on the SF Oracle RAC cluster nodes
          1.  
            Issues during fencing startup on SF Oracle RAC cluster nodes set up for server-based fencing
        12. Issues during online migration of coordination points
          1.  
            Vxfen service group activity after issuing the vxfenswap command
      7. Troubleshooting Cluster Volume Manager in SF Oracle RAC clusters
        1.  
          Restoring communication between host and disks after cable disconnection
        2.  
          Shared disk group cannot be imported in SF Oracle RAC cluster
        3.  
          Error importing shared disk groups in SF Oracle RAC cluster
        4.  
          Unable to start CVM in SF Oracle RAC cluster
        5.  
          CVM group is not online after adding a node to the SF Oracle RAC cluster
        6.  
          CVMVolDg not online even though CVMCluster is online in SF Oracle RAC cluster
        7.  
          Shared disks not visible in SF Oracle RAC cluster
      8. Troubleshooting CFS
        1.  
          Incorrect order in root user's <library> path
      9. Troubleshooting interconnects
        1.  
          Example entries for mandatory devices
      10. Troubleshooting Oracle
        1.  
          Error when starting an Oracle instance in SF Oracle RAC
        2.  
          Clearing Oracle group faults
        3.  
          Oracle log files show shutdown called even when not shutdown manually
        4.  
          DBCA fails while creating an Oracle RAC database
        5.  
          Oracle's clusterware processes fail to start
        6.  
          Oracle Clusterware fails after restart
        7.  
          Troubleshooting the Virtual IP (VIP) configuration in an SF Oracle RAC cluster
        8.  
          Troubleshooting Oracle Clusterware health check warning messages in SF Oracle RAC clusters
      11. Troubleshooting ODM in SF Oracle RAC clusters
        1.  
          File System configured incorrectly for ODM shuts down Oracle
      12.  
        Troubleshooting Flex ASM in SF Oracle RAC clusters
    2. Prevention and recovery strategies
      1.  
        Verification of GAB ports in SF Oracle RAC cluster
      2.  
        Examining GAB seed membership
      3.  
        Manual GAB membership seeding
      4.  
        Evaluating VCS I/O fencing ports
      5.  
        Verifying normal functioning of VCS I/O fencing
      6. Managing SCSI-3 PR keys in SF Oracle RAC cluster
        1.  
          Evaluating the number of SCSI-3 PR keys on a coordinator LUN, if there are multiple paths to the LUN from the hosts
        2.  
          Detecting accidental SCSI-3 PR key removal from coordinator LUNs
      7.  
        Identifying a faulty coordinator LUN
    3. Tunable parameters
      1.  
        About SF Oracle RAC tunable parameters
      2. About GAB tunable parameters
        1.  
          About GAB load-time or static tunable parameters
        2.  
          About GAB run-time or dynamic tunable parameters
      3. About LLT tunable parameters
        1.  
          About LLT timer tunable parameters
        2.  
          About LLT flow control tunable parameters
        3.  
          Setting LLT timer tunable parameters
      4. About VXFEN tunable parameters
        1.  
          Configuring the VXFEN module parameters
      5.  
        Tuning guidelines for campus clusters
  3. Section III. Reference
    1. Appendix A. List of SF Oracle RAC health checks
      1.  
        LLT health checks
      2.  
        I/O fencing health checks
      3.  
        PrivNIC health checks in SF Oracle RAC clusters
      4.  
        Oracle Clusterware health checks in SF Oracle RAC clusters
      5.  
        CVM, CFS, and ODM health checks in SF Oracle RAC clusters
    2. Appendix B. Error messages
      1.  
        About error messages
      2.  
        VxVM error messages
      3. VXFEN driver error messages
        1.  
          VXFEN driver informational message
        2.  
          Node ejection informational messages

Clearing preexisting split-brain condition

Review the information on how the VxFEN driver checks for preexisting split-brain condition.

See Fencing startup reports preexisting split-brain.

See About the vxfenclearpre utility.

Table: Recommened solution to clear pre-existing split-brain condition describes how to resolve a preexisting split-brain condition depending on the scenario you have encountered:

Table: Recommened solution to clear pre-existing split-brain condition

Scenario

Solution

Actual potential split-brain condition - system 2 is up and system 1 is ejected

  1. Determine if system1 is up or not.

  2. If system 1 is up and running, shut it down and repair the private network links to remove the split-brain condition.

  3. Restart system 1.

Apparent potential split-brain condition - system 2 is down and system 1 is ejected

(Disk-based fencing is configured)

  1. Physically verify that system 2 is down.

    Verify the systems currently registered with the coordination points.

    Use the following command for coordinator disks:

    # vxfenadm -s all -f /etc/vxfentab

    The output of this command identifies the keys registered with the coordinator disks.

  2. Clear the keys on the coordinator disks as well as the data disks in all shared disk groups using the vxfenclearpre command. The command removes SCSI-3 registrations and reservations.

    See About the vxfenclearpre utility.

  3. Make any necessary repairs to system 2.

  4. Restart system 2.

Apparent potential split-brain condition - system 2 is down and system 1 is ejected

(Server-based fencing is configured)

  1. Physically verify that system 2 is down.

    Verify the systems currently registered with the coordination points.

    Use the following command for CP servers:

    # cpsadm -s cp_server -a list_membership 
-c cluster_name

    where cp_server is the virtual IP address or virtual hostname on which CP server is configured, and cluster_name is the VCS name for the SF Oracle RAC cluster (application cluster).

    The command lists the systems registered with the CP server.

  2. Clear the keys on the coordinator disks as well as the data disks in all shared disk groups using the vxfenclearpre command. The command removes SCSI-3 registrations and reservations.

    After removing all stale registrations, the joiner node will be able to join the cluster.

  3. Make any necessary repairs to system 2.

  4. Restart system 2.