In doing some background research for a post on FT vs. MSCS, I stumbled upon a wonderful write up by Brian Atkinson aka. “VMRoyale”, on FT’s laundry list of requirements, limits, and other considerations. The original post is here. He does an excellent job of pulling together data from various VMware docs and puts together quite the list, of which I’ll only borrow from here:
- VMware FT is available in the following versions of vSphere: Advanced, Enterprise, Enterprise Plus
- VMware FT requires virtual machines to have thick-eager zeroed disks. Thin or sparsely allocated disks will be converted to thick-eager zeroed when VMware FT is enabled requiring additional storage space. The virtual machine must be in a powered-off state to take this action.
- Ensure that the processors are supported: AMD Barcelona+, Intel Penryn+ (Download VMware SiteSurvey.)
Intel Xeon based on 45nm Core 2 Microarchitecture Category:
- Virtual machines must be running on one of the supported guest operating systems. See the VMware knowledge base article 1008027 for more information.
- The combination of the virtual machine’s guest operating system and processor must be supported by Fault Tolerance (for example, 32-bit Solaris on AMD-based processors is not currently supported).
- Ensure that HV (Hardware Virtualization) is enabled in the BIOS.
- Ensure that FT protected virtual machines are on shared storage (FC, iSCSI or NFS).
- Ensure that the datastore is not using physical RDM (Raw Disk Mapping). Virtual RDM is supported. \
The entire thing is worth a once over if you are considering VMware’s FT in your environment.