Veritas High Availability 7.4.2 Solution Guide for VMware - Linux

Last Published:
Product(s): InfoScale & Storage Foundation (7.4.2)
Platform: Linux
  1. Introducing the Veritas High Availability solution for VMware
    1. How the Veritas High Availability solution works in a VMware environment
      1.  
        How the Veritas HA Plug-in for vSphere Web Client works with VCS
      2.  
        How the VMwareDisks agent communicates with the vCenter Server instead of the ESX/ESXi host
      3.  
        Getting started with vCenter-integrated Veritas High Availability solution
      4. Getting started with the VIOM-integrated Veritas High Availability solution
        1.  
          About administering high availability with VOM
      5. Understanding Veritas High Availability terminology
        1.  
          Understanding operation names
      6.  
        Supported VMware versions
      7.  
        Important release information
  2. Deploying the Veritas High Availability solution
    1.  
      Managing storage
    2.  
      Installing the Veritas High Availability guest components
    3.  
      Upgrading Veritas High Availability guest components
  3. Administering application availability from the vSphere Client
    1.  
      Accessing the Veritas High Availability view
    2. Administering application monitoring from the Veritas High Availability view
      1. Understanding the Veritas High Availability view
        1.  
          To view the status of configured applications
      2.  
        Configuring a cluster by using the VCS cluster configuration wizard
      3.  
        To configure or unconfigure application monitoring
      4.  
        Adding a system to a VCS cluster
      5.  
        To start or stop applications
      6.  
        To switch an application to another system
      7.  
        To add or remove a failover system
      8.  
        To suspend or resume application monitoring
      9.  
        To clear Fault state
      10.  
        To resolve a held-up operation
      11.  
        To determine application state
      12.  
        To remove all monitoring configurations
      13.  
        To remove VCS cluster configurations
    3.  
      Administering application monitoring settings
    4. Administering application availability using Veritas High Availability dashboard
      1. Understanding the dashboard work area
        1.  
          Aggregate status bar
        2.  
          ESX cluster/host table
        3.  
          Taskbar
        4.  
          Filters menu
        5.  
          Application table
      2. Accessing the dashboard
        1.  
          Prerequisites for accessing the dashboard
        2.  
          How to access the dashboard
        3.  
          Who can access the dashboard
      3.  
        Monitoring applications across a data center
      4.  
        Monitoring applications across an ESX cluster
      5.  
        Searching for application instances by using filters
      6.  
        Selecting multiple applications for batch operations
      7.  
        Starting an application using the dashboard
      8.  
        Stopping an application by using the dashboard
      9.  
        Entering an application into maintenance mode
      10.  
        Bringing an application out of maintenance mode
      11.  
        Switching an application
      12.  
        Resolving dashboard alerts
  4. Appendix A. Roles and privileges
    1.  
      About the roles and privileges assigned in vCenter
    2. Assigning customized privileges to VMwareDisks agent
      1.  
        About assigning privileges to VMwareDisks agent
      2.  
        Creating a role with customized privileges for VMwareDisks agent
      3.  
        Creating an ESX user account
      4.  
        Integrating an ESX user account with Active Directory
      5.  
        Assigning a role to an ESX user account
  5. Appendix B. Troubleshooting
    1.  
      Agent logging on virtual machine
    2. Troubleshooting wizard-based configuration issues
      1.  
        Veritas High Availability Configuration wizard displays the "hadiscover is not recognized as an internal or external command" error
      2.  
        Running the 'hastop -all' command detaches virtual disks
      3.  
        Validation may fail when you add a failover system
      4.  
        Adding a failover system may fail if you configure a cluster with communication links over UDP
    3. Troubleshooting issues with the Veritas High Availability view
      1.  
        Veritas high availability view is not visible from a cluster system
      2.  
        Veritas High Availability view does not display the application monitoring status
      3.  
        Veritas High Availability view may freeze due to special characters in application display name
      4.  
        If the Console host abruptly restarts, the high availability view may disappear
      5.  
        Veritas high availability view may fail to load or refresh
      6.  
        Operating system commands to unmount resource may fail

How the VMwareDisks agent communicates with the vCenter Server instead of the ESX/ESXi host

In addition to the ESX hosts the VMwareDisks agent can also communicate the disk detach and attach operations with the vCenter Server to which the virtual machines belong.

In this scenario, in event of a failure, the VMwareDisks agent sends the disk detach and attach requests to the vCenter Server (instead of the ESX hosts). The vCenter Server then notifies the ESX host for these operations. Since the communication is directed through the vCenter Server, the agent successfully detaches and attaches the disks even if the ESX host and the virtual machines reside in a different network.

In a scenario where the host ESX/ESXi itself faults, the VMareDisks agent from the target virtual machine sends a request to the vCenter Server to detach the disks from the failed virtual machine. However, since the host ESX has faulted, the request to detach the disks fails. The VMwareDisks agent from the target virtual machine now sends the disk attach request. The vCenter Server then processes this request and disks are attached to the target virtual machine. The application availability is thus not affected.

Limitation

The configuration of VMwareDisks agent to communicate with the vCenter Server has the following limitation:

If VMHA is not enabled and the host ESX faults, then even after the disks are attached to the target virtual machine they remain attached to the failed virtual machine. This issue occurs because the request to detach the disks fails since the host ESX itself has faulted. The agent then sends the disk attach request to the vCenter Server and attaches the disks to the target virtual machine.

Even though the application availability is not impacted, the subsequent power ON of the faulted virtual machine fails. This issue occurs because of the stale link between the virtual machine and the disks attached. Even though the disks are now attached to the target virtual machine the stale link with the failed virtual machine still exists.

Workaround

As a workaround, you must manually detach the disks from the failed virtual machine and then power ON the machine.

About the vCenter Server user account privileges

You must have the administrative privileges or must be a root user to communicate the disk detach and attach operations through the vCenter Server. If the vCenter Server user account fails to have the administrative privileges or is not a root user, then the disk detach and attach operation may fail, in event of a failure.

If you do not want to use the administrator user account or the root user, then you must create a role and add the following privileges to the created role:

  • "Low level file operations" on datastore

  • "Add existing disk" on virtual machine

  • "Change resource" on virtual machine

  • "Remove disk" on virtual machine

After you create a role and add the required privileges, you must add a local user to the created role. You can choose to add an existing user or create a new user.

Refer to the VMware product documentation for details on creating a role and adding a user to the created role.