Tag Archives: high availability

VCAP-DCA Study Notes – 2.3 Deploy and Maintain Scalable virtual networks


  • Identify VMware NIC Teaming policies
  • Identify common network protocols

Skills and Abilities

  • Understand the NIC Teaming failover types and related physical network settings
  • Determine and apply Failover settings
  • Configure explicit failover to conform with VMware best practices
  • Configure port groups to properly isolate network traffic

Tools & learning resources

Identify, understand , and configure NIC teaming

The five available policies are;

  • Route based on virtual port ID (default)
  • Route based on IP Hash (MUST be used with static Etherchannel – no LACP). No beacon probing.
  • Route based on source MAC address
  • Route based on physical NIC load (vSphere 4.1 only)
  • Explicit failover

NOTE: These only affect outbound traffic. Inbound load balancing is controlled by the physical switch.

Continue reading VCAP-DCA Study Notes – 2.3 Deploy and Maintain Scalable virtual networks

VCAP-DCA Study Notes – 4.2 Deploy and test VMware FT

The main document to work through for the VCAP-DCA is the Availability Guide but there are plenty of good white papers and blog posts which give useful background information (see the bottom of this post). If you have access to the 2010 VMworld content it’s worth watching session BC8274 which covers most of the material on the blueprint.


  • Identify VMware FT hardware requirements
  • Identify VMware FT compatibility requirements

Skills and Abilities

  • Modify VM and ESX/ESXi Host settings to allow for FT compatibility
  • Use VMware best practices to prepare a vSphere environment for FT
  • Configure FT logging
  • Prepare the infrastructure for FT compliance
  • Test FT failover, secondary restart and application fault tolerance in a FT Virtual Machine

FT requirements (hardware, software and feature compatibility)

  • Firstly you have to make sure your host hardware will support FT – it’s more demanding than many other VMware features.
    • The main requirement is to have Intel Lockstep technology support in the CPUs and chipset. Rather than list the processor families which support FT you can read VMwareKB1008027.
    • Hardware virtualisation must also be enabled in the BIOS (not always on by default).
  • You need to ensure the guest OS and CPU combination is supported (as the Availability Guide states, Solaris on AMD is not for example).
  • Must have HA enabled on the cluster
  • Licencing– you need Advanced or higher to run FT
  • Host certificates need to be enabled. If you did a clean install of vSphere 4.x this is enabled by default but if you upgraded from VI3.x you have to explicitly enable it (vCentre settings, SSL)
  • Should avoid mixing ESX and ESXi hosts in a cluster with FT-enabled VMs (VMwareKB1013637)

There are also VM level requirements;

  • No USB or sound devices
  • No NPIV
  • No paravirtualized guest OS
  • No physical mode RDMs
  • Hot plug (memory, CPU, hard disks etc) is automatically disabled for FT-enabled VMs
  • No Serial or parallel ports

FT places quite a few restrictions on the features you can use;

Continue reading VCAP-DCA Study Notes – 4.2 Deploy and test VMware FT

VCAP-DCA Study Notes – 4.3 Supporting MS Clustering in vSphere

The main guide for this section is the ‘Setup for Failover clustering and Microsoft Cluster Service’ whitepaper. It’s a difficult topic to test in a lab unless you’re lucky enough to have FC in your lab! Very little has changed in regards to running MSCS on VMware since the VI3 days so if you’re familiar with that (and it was on the VCP syllabus) then don’t read any further! If you want a refresher however (and a few tidbits which are new to vSphere 4.1), read on….


  • Identify MSCS clustering solution requirements
  • Identify the three supported MSCS configurations

Skills and Abilities

  • Configure Virtual Machine hardware to support cluster type and guest OS
  • Configure a MSCS cluster on a single ESX/ESXi Host
  • Configure a MSCS cluster across ESX/ESXi Hosts
  • Configure standby host clustering

Tools & learning resources

Supported MSCS configurations

Three options;

  • Cluster in a box
  • Cluster across boxes
  • Standby (one physical node, one virtual node)

Solution requirements

Physical hardware

One of the main requirements is a FC SAN (this is one of the rare features which doesn’t work with NFS).

Continue reading VCAP-DCA Study Notes – 4.3 Supporting MS Clustering in vSphere