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The Turn on Fault Tolerance option is disabled

Symptoms

  • When selecting a virtual machine to enable Fault Tolerance, you find that the Turn on Fault Tolerance option is greyed out
  • The Turn on Fault Tolerance option is disabled
  • Cannot turn on Fault Tolerance

Resolution

For the Turn on Fault Tolerance option to be visible, the these requirements must be met. If any of the following is not configured correctly, the option is not displayed. Ensure each of the following are properly setup:
  1. Ensure VMware software compatibility. All versions of the VMware software used in a Fault Tolerance environment must be compatible. Ensure the versions installed at your site are listed as compatible at http://www.vmware.com/pdf/vsphere4/r40/vsp_compatibility_matrix.pdf.

  2. On a hardware and guest operating system level, only certain processors and operating systems are supported. For more information on this support, see Processors and Guest Operating Systems that support VMware Fault Tolerance (1008027).

    Note: SMP (Multiprocessor) virtual machines are not supported with VMware Fault Tolerance at this time

  3. Hardware Virtualization (HV) must be enabled in the BIOS for each host in the cluster. The process for enabling HV differs in each BIOS. For this reason, contact your hardware vendor for instructions on enabling HV.

  4. All ESX hosts used by VMware Fault Tolerance must be members of a VMware High Availability (HA) cluster. VMware HA must be enabled for VMware Fault Tolerance to function. Instructions for enabling VMware HA can be found in the vSphere Availability Guide.

  5. The ESX hosts that run the primary and secondary Fault Tolerance nodes, must be running the same build of ESX. Additionally, patches have been released that contain improvements to the VMware Fault Tolerance features. For this reason, VMware strongly suggests updating to the most current version available. Instructions for updating hosts can be found in the VMware vCenter Update Manager Administration Guide , or ESX 4 Patch Management Guide.

  6. There are several important considerations relative to storage for VMware Fault Tolerance. Ensure each of the following are configured for your environment to enable VMware Fault Tolerance:

    1. The virtual machine must reside on shared storage. This is storage that is visible to all ESX hosts in the cluster.
    2. Storage must be FC SAN, iSCSI or NFS, but not local storage.
    3. Virtual RDMs are supported, but Physical RDMs are not.
    5. Virtual machines cannot have snapshots. If there are snapshots, these must be committed before proceeding.

  7. Networking must be configured properly to ensure proper VMware Fault Tolerance functionality. Ensure each of the following is defined appropriately:
    1. A separate VMkernel port group must be defined for FTLogging. Instructions for creating this portgroup can be found in the Networking chapter of the ESX Configuration Guide.
    2. FTLogging and VMotion portgroups must be defined and assigned a physical network card for uplink. This network card must be at least 1Gb, with a 10Gb card preferred.
    3. Enable use of Jumbo Frames for the FTLogging. For detailed steps, see the Advanced Networking section of the ESX Configuration Guide.
    4. VMware recommends enabling fully redundant NICs to ensure availability, though Fault Tolerance can function without it.
    5. In environments with constrained bandwidth, network utilization can be lowered by following the instructions in Reducing FT logging traffic for disk read intensive workloads (1011965).
 
For more information about VMware Fault Tolerance, refer to the article: VMware Fault Tolerance FAQ (1013428)

Additional Information

Additional information regarding VMware Fault Tolerance can be found in the vSphere Availability Guide.

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Actions
  • KB Article: 1010631
  • Updated: Aug 20, 2009
  • Products:
    VMware ESX
    VMware ESXi
  • Product Versions:
    VMware ESX 4.0.x