As effective and useful as virtualization has proven to be for business IT, a number of virtualization myths are still in circulation, and widely believed by many IT pros. These can range from the overly positive (such as the “virtualization as a silver bullet” theory) to outright falsehoods (you need to know Linux to use VMware).
1. Virtualization is only good for server consolidation.
In some respects, virtualization has become a victim of its own success. Server consolidation via virtualization has saved many IT departments millions of dollars in hardware and power costs, but also contributes to the perception among some IT pros that virtualization is just a server-side solution. Schutz explains that the impressive space and cost saving that server consolidation brings is a huge benefit, but “it’s really the low-hanging fruit” when it comes to a more substantial virtualization strategy. Virtualization has the potential to revolutionize how enterprise IT is done, but IT pros should also consider desktop virtualization, application virtualization, and other uses for virtualization in their organizations.
=> Note that virtualization started with the client, VMware workstation for example, and then got into the server market with the products we know today.
2. VMware doesn’t take advantage of multi-core systems.
This myth has been circulating for years, and VMware’s Anderson indicates that the ESX Server family of products has been taking advantage of multi-core processors for a long time. While multi-core support in ESX server is now a given, Anderson points out that some applications have hard-coded limitations when it comes to memory and processor requirements, and those apps still need to abide by those restrictions when running in a virtual machine. For example, Microsoft recommends 32GB of memory per operating system instance and 1000 mailboxes per processor core as a guideline for Exchange deployments, and those guidelines still apply when Exchange is virtualized.
=> Not only it does take advantages of multi-core systems but also within the guest with SMP capabilities, up to vCPU for the moment and in the free version as well, something Hyper-V doesn’t offer right now.
3. Virtualization is a silver bullet.
Virtualization can do wonders when it comes to increasing efficiency and power savings, but it can’t do it all. Some IT pros don’t research the downside of virtualization fully, which leads to the misconception that virtualization is a silver bullet that can solve all your IT problems. “Some believe it can take away all the pain, that it’s a magic pill,” says Schutz. “Virtualization can provide great tools, but without effective management, the benefits of what virtualization brings will go untapped.”
=> The same process goes for virtualization, you have to design, implement, monitor, etc…
4. Virtualization doesn’t work for high I/O applications.
The conventional wisdom used to be that virtualization wouldn’t work well with apps that had high I/O demands. Anderson agrees that this may have been an issue in the early days of virtualization, but virtualization technology has made great strides in this area over the last five years. For example, VMware recently demonstrated a version of ESX Server running more than 100,000 I/O operations per second on one ESX host.
=> Put that in another word, a single virtual machine can kill your storage IOPS!!! So pay attention again and keep on monitoring.
5. To use VMware you need to know Linux.
In the early days of VMware, several of VMware’s products required use of a Linux command line console to access some management functions. While that command line support is still available, most VMware customers will never need to touch a command line to perform management functions. “We have many Windows-based installations where administrators never have to use those command line features,” Anderson says. “That functionality is still there, but you don’t need to use it to manage your VMware deployments.”
=> Although you will feel comfortable if you have a Unix/Linux background, this can be learned as you go with it.
Full article here
And now a funny video from Microsoft: Microsoft Myth busters: Top 10 VMware Myths, busting the top ten myths about VMware virtualization from Microsoft
Myth #1, 2 only available in Hyper-V version 2, not out yet, still in beta !
Myth #3, well whatever version it is, it is missing enterprise features only available (soon) in version 2, oops, next release J
Myth #4, again the fact that the current release doesn’t have some features like the ‘lock page in memory’ make it a bit slower than ESX. Next release MS will recover the gap I hope
Myth #5, footprint of an ESXi is below than 50MB disk wise, Microsoft’s free version is … 1GB! But has Microsoft says, who cares.
Myth #6, having the drivers certified for either VMware or Microsoft doesn’t mean they are bug free. But that’s true you can built a Hyper-V any hardware supported by Windows and that means much much more hardware than ESX
Myth #7, I agree
Myth #8, memory overcommit is definitely useful to achieve a bigger consolidation ratio but when you actually using the disk as memory you just kill the performance! Hopefully if you run DRS, the guest would be migrated with vMotion to another host with enough memory resources. Of course you need vMotion or Live Migration, so my bet Microsoft will have the same feature soon in a future release of Hyper-V now that they will be able to live migrate guests.
Myth #9, that’s fair, VMware remains an expensive product…
Myth #10, hey Microsoft where is you virtualization layer gone !?