VMware FT

Version 8

    FT Information

    http://www.vmware.com/products/fault-tolerance/

    Meet the Engineer Series: VMware Fault Tolerance

    A Summary of FT Related Documents

    http://www.vmware.com/files/pdf/perf-vsphere-fault_tolerance.pdf - VMware vSphere™ 4 Fault Tolerance: Architecture and Performance

    http://www.vmware.com/files/pdf/resources/ft_virtualization_wp.pdf - Protecting Mission-Critical Workloads with VMware Fault Tolerance

    http://kb.vmware.com/kb/1010601 - Understanding VMware Fault Tolerance

    http://kb.vmware.com/kb/1013428 - VMware Fault Tolerance FAQ

    http://tech.philipsellers.com/2008/09/20/introduction-to-vmware-ft-fault-tolerence/

    http://www.virtualizationteam.com/virtualization-vmware/vmware-esx-40-ft-fault-tolerant-sneak-peek.html - VMware ESX 4.0 FT – Fault Tolerant – Sneak Peek

    FT not supported on Nehalem systems with hyperthreading enabled?

     

    About vLockStep:

    http://software.intel.com/en-us/blogs/2009/05/28/instruction-level-lock-step-parallelism-on-desert-islands/

    http://mordtech.com/tag/vlockstep/

     

    Demo of VMware's vSphere Fault Tolerance (FT)

     

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    FT requirements

    http://www.ntpro.nl/blog/archives/1090-Fault-Tolerance-Checklist.html

     

    • Only some CPU can be used: http://kb.vmware.com/kb/1008027 - Processors and guest operating systems that support VMware Fault Tolerance

    • Hardware Virtualization (HV) must be enabled in the BIOS for each host in the cluster (but this is also required for EVC and x64 VMs)

    • The ESX hosts that run the primary and secondary Fault Tolerance nodes, must be running the same build of ESX.

    • 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.

    • Networking must be configured properly to ensure proper VMware Fault Tolerance functionality.

    • In some cases the VM must be powered off to enable FT (for some guest type and to convert vmdk from zeroedthick to eagerzeroedthick )

     

    To check compatibility there is also a VMware utility:

    Site Survey - http://www.vmware.com/download/shared_utilities.html

     

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    FT 1.0 limitations

     

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    FT 1.0 best practices

    • Use dedicated 1Gb (better if is 10Gbs) link for FT logging

    • Use SVMotion to converter from thin to thick, or use dastore browser/inflate (but in this case the VM must be powered off)

    • Use CPU with similar speed

    • Do not use CPU power management

    • With Nehalem CPU, HT could be enable without problem (and is also suggested by VMware)

    • Enable FT with the VM powered off

     

    See also: http://www.vmware.com/files/pdf/fault_tolerance_recommendations_considerations_on_vmw_vsphere4.pdf

     

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    FT vs VM HA or MSCS

    FT does not protect against OS or application failures, only from ESX host failures.

     

    See also:

    Clarificaiton on Fault Tolerance

    http://blog.scottlowe.org/2009/10/30/vmware-ha-vmware-ft-and-os-clustering/

     

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    VMware FT vs Marathon eveRun

    http://www.yellow-bricks.com/2008/09/24/marathon-haft-vs-vmware-haft/

    http://www.mikedipetrillo.com/mikedvirtualization/2008/09/marathon-and-vmware-ft.html

    http://www.mikedipetrillo.com/mikedvirtualization/2008/09/marathon-everrun-vs-vmware-ha-another-mess.html

    http://itknowledgeexchange.techtarget.com/server-virtualization/vmware-defends-its-upcoming-fault-tolerance-feature/

    http://channelvirtualization.wordpress.com/2008/09/18/marathon-on-vmwares-ft-sort-of-fault-tolerance/

     

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    Enable/Disable FT with script

    Could be useful to implement some backup solution on FT protected VM.

    on-demand FT, can this be automated?

    ftCLI.pl - VMware Fault Tolerant Managment