Virtualization high availability architecture guide for VARs

Although implementing a virtualization high availability (HA) architecture may seem like an enticing option for cash-strapped customers, solution providers should know the HA requirements and its potential drawbacks.

Now that you’ve installed and set up a hypervisor for your customer, they may ask you about installing a high-availability (HA) architecture in their environment. While this isn’t an easy process, it’s one that could be mutually beneficial for VARs and customers. HA can be a great value-add and provide future opportunities for VARs. For customers, HA provides some peace-of-mind with quick VM reboot after a host failure and almost 100% uptime. In this guide, you can compare the HA solutions for Hyper-V, VMware and XenServer along with some advice for weighing vendor offerings and some trouble spots in virtualization HA.


FAQ: Hyper-V high availability requirements for VARs
Implementing Hyper-V high availability (HA) isn’t as simple as flipping a switch but can be a good opportunity for a value-add. Solution providers should carefully analyze their customer’s environment and decide if features such as Cluster Shared Volumes are a necessity. Check out our expert’s HA best practices, useful cmdlets and how to use the Best Practices Analyzer (BPA) in this FAQ.

Three setbacks when designing Hyper-V R2 High Availability
Prepare yourself for the potential pitfalls of designing Hyper-V R2 HA for customers by reading these three setbacks for VARs to consider. Taking the time to spec out hosts for customers, for example, and limiting the number of assigned virtual processors so they’re fewer than the number of physical processors can help avoid Hyper-V memory bottlenecks.

How to select Hyper-V high-availability hardware
Most VARs know that selecting high-availability hardware compatible with Hyper-V’s requirements is only the first step to picking the right hardware. VARs also need to consider additional support for Second-Level Address Translation (SLAT) hardware and decide on filling their customer’s environment with either a large number of hosts or fewer, stronger ones.


VMware High Availability and Fault Tolerance FAQ
For solution providers looking for a crash course on VMware HA, this FAQ will give you the basics on HA and fault tolerance (FT). Find out what separates VMware HA from other offerings as well as some pros and cons to keep in mind when detailing the feature to customers.

Don't misuse VMware high-availability technology
VMware HA technology can be an effective tool for VARs, but they should keep in mind it has limitations as a disaster recovery (DR) solution. It’s your job to remind customers that these HA tools don’t double as DR solutions but vendors can offer availability to the OSes services, such as VMware’s application monitoring. Solution providers also need to keep customer expectations in check and explain that 100% availability may not necessarily be a goal they want to pay to achieve.

High-availability and clustering solutions for vSphere VMs
With the numerous vSphere HA features out there, knowing the different clustering layers that fit with each failure in the computing stack is important for VARs. This tip explains what HA Application Monitoring can do for application clustering in vSphere 4.1.

More resources on Virtualization high availability architectures

High-availability architecture: Redundancy vs. abstraction
When your customers query you on using virtualization to save them money, implementing resiliency in a HA architecture will have to be part of the discussion. Solution providers can go down two paths with resiliency: Using redundant hardware or resiliency through abstraction. Learn the right situation to use each method and how they can often work in unison.

Citrix XenServer 5.5 high-availability setup
Take a look at each step of setting up Citrix XenServer 5.5 HA for your customers, starting with the minimum requirements such as Citrix Essentials. Also included are VAR installation tips, such as ensuring VM protection, and how to activate and use XenServer HA.

Virtualization high availability checklist
Avoid major issues when working on a customer’s data center HA deployment by knowing the ins and outs of this virtualization HA checklist. Some items on the list may be relatively obvious to VARs, such as testing failover/failback regularly, but there are others that may be more subtle but just as important, including evaluating a single storage area network (SAN) switch.

Reserving cluster resources to boost high availability
Your customers may be filling your inbox with questions about HA, but you need to carefully consider the amount of cluster resources you’re using before making any decisions. Learn the situations where unused cluster resources aren’t a deal-breaker for customers and how to reserve cluster resources. Solution providers can also get a look at other ways to ensure HA in this tip.

Server cluster high-availability gotchas: DNS and failover
HA is not necessarily a panacea for all VAR customer environmental ailments. Beyond being able to reboot VMs after a host failure, there is a lot that can go wrong with HA. Read why domain name system (DNS) resolution can be an issue when implementing VMware HA and other gotchas to be wary of.

Testing high-availability software options from vendors
A critical decision when weighing HA architecture options for your customers is picking the right software. Solution providers can thoroughly test software for failover capabilities or the effect of shared storage options can have on VARs, such as having to contact a storage administrator whenever deploying a new VM before helping a customer make the right choice.

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