Last week, we took a look at some of the cost-related comparisons between RHEV, vSphere, and Hyper-V. That’s all fine and dandy, but to make the most of the comparison, and really put it into perspective, we need to show what you get for the money.
If cost was the only factor, we’d all be driving Kia’s
And while performance is great too, it’s not the only consideration. If that were the case, we’d all be driving Porche’s, Ferrari’s, etc. The point being is that there are always a number of factors in any major decision, whether its a car or a virtualization platform.
Today’s post starts to show what you get for your virtualization investment. And while the previous post was a clear shot across the bow in regards to cost, this week’s post is potentially less clear. Not because I can’t explain it (I can), but because it’s all about what you need in your environment and what’s important to you (Only you know that). I have a clear winner based on what is important to me (feature-wise), but you may have some other features that you want.
So, first off, I’ll show you some of the basics in terms of hardware and virtual hardware limits. It’s important to understand that while both vSphere and Hyper-V have different tiers (Enterprise, Enterprise Plus, Standard, Data Center, etc), RHEV does not. When you purchase a support subscription for RHEV, you get everything. vSphere and Hyper-V may require you to purchase a more expensive product to get the same functionality.
|RHEV 3.0||vSphere 5||Hyper-V|
|Hypervisor Max CPU||160 physical CPUs||160 cores||64|
|Hypervisor Max RAM||2TB, 64TB theoretical||2TB||2TB|
|Guest Max CPU||64||32||4|
|Guest Max RAM||512GB||1TB||64GB|
|Guest Max Storage Dev 16||25||60||4|
|Guest Max vNIC||16||10^7||12|
|Max Hosts per Mgmt||500||1000||unclear|
|Max ActiveGuests per Mgmt||10000||10000||384|
Ok, so right off the bat, Hyper-V doesn’t even compare. Period. Keep in mind that in the last post I showed where Hyper-V cost almost as much as vSphere. It’s like paying double for a “Yugo” because it’s got leather. Beyond that, RHEV and vSphere are close in Hypervisor RAM, and maximum Active Guests per management portal. vSphere has it made in the shade regarding maximum number of storage devices and maximum vNICs in guests. But do you really have a use case for a VM needing more than 16 vNICs? (If you do, feel free to post it in the comments section.)
Let’s move on to some of the actual features. And yes, I’m aware that Red Hat, VMWare, and Microsoft all post similar things on their sites and spin it in a way that favors their product. That’s fine, but this is my blog, and this is what’s important to me.
|RHEV 3.0||vSphere 5||Hyper-V 2008 R2|
|Small Footprint Hypervisor||yes||yes||no|
|Processor Hardware Memory Assist||yes||yes||no|
|VLAN Support||yes||yes||Requires Host & Guest Config|
|High Availability for VMs||yes||Requires Advanced or Higher||Requires Windows Clustering|
|Live Migration||yes||Requires Advanced or Higher||Requires Windows Clustering|
|Shared Resource Pools||yes||yes||yes|
|Cluster Resource Policies||yes||Enterprise & Enterprise Plus||no|
|Thin Provision Guests||yes||yes||yes|
|Central Management||yes||yes||Requires Multiple Products|
|RBAC Policies for Admins & Users||yes||yes||yes|
If you look at the Hyper-V column, you’ll notice a lot of “no” and “requires…” type comments. I’m not likely going to include Hyper-V in many more posts. Or maybe I’ll just leave it as an example of what not to buy. (To be fair, when the next version of Hyper-V comes out, I will play nicely and write an update.)
Moving on, (almost*) all of the other comparisons put RHEV on par with vSphere in the areas that are important to me. Yes, vSphere has many more components that I have not listed and many of those do not have an analog in RHEV. But again, (almost all of *) the pieces and features that are important to me (memory sharing, VLAN support, live migration, etc) are all covered.
For less money.
What about the “*”, you say? What about the most important feature? You’ll have to come back for the next post. 😉
Hope this helps,