What (really) VMware ESX 3i is (to me)

Last week, at VMworld 2007 in San Francisco, VMware announced ESX 3i. There have been lots of speculations within the virtualization community about what ESX 3i would have looked like. And now it's here. So what (really) is this thing and what does it mean for the industry? I personally think that 3i is a good technology step forward, a great marketing announcement and a tremendous potential point of control for VMware. Read on if you want to know more (about what I think).

A good technology step forward

A few weeks ago I wrote a post about the high level architecture of some of the hypervisors currently available (or due shortly). I encourage you have a look at it if interested as it will serve as a background for the next few comments. It is obvious that ESX has always been a complex beast but in reality in its essence it is a hypervisor (with integrated device drivers as opposed to other hypervisor architectures) that is "serviced" by a so called ... guess what ... "Service Console" (or Console OS - COS for short). The easiest way to picture the COS is to think about it as a Linux based system virtual machine. It is there for a number of reasons but it runs above the hypervisor portion and not underneath it. ESX 3i is basically the same ESX we used to know without the Service Console instance. This is not exactly true since some of the functions of the COS had to be ported to the hypervisor (for example the COS allowed the hypervisor to boot up) but you pretty much get the picture. That's why VMware claims that they have been able to reduce the ESX footprint from 2GB down to 32MB (that is in fact the rough size of the COS and of the hypervisor). So in summary the "legacy" ESX 3 is 2GB+32MB while ESX 3i is just 32MB.

So what does this buy you as an end user? Yes me too I think... not so much. Sure it has a much smaller attack surface for viruses and security vulnerability that means less updates so less troubles for system administrators. Also it finally allows to get rid of these legacy 2 hard disk drives in rack servers and more importantly blades transforming them in true stateless devices ... as they should be. Yet not really something you would go through the streets of San Francisco screaming "oh boy what they managed to invent!?!"

This is not, as many speculated prior to the announcement, a "hypervisor on a chip" or an "ESX on the motherboard". It is a pretty standard ESX 3 hypervisor that got rid of the not necessary bits and that happens to be installed on a new media (i.e. a flash drive) rather than on standard hard drives. It won't buy you any performance improvement, and certainly it has not changed the overall architecture and lay out of the ESX solution. So to me it's a good piece of technology, not the end of the world.

A great marketing announcement

"This is a hypervisor on a chip, ESX on the motherboard if you will. The footprint has been reduced from 2GB to 32MB; can you imagine the performance improvements and the robustness associated?"

Now let me tell you folks, I have been working very closely with many sales representatives during my career and I bet this is what they would get out of ESX 3i. And don't get me wrong I am not saying that they are going to cheat their customers... it might very well be that they believe in what they are saying. Similarly to the current feeling that using CPU hardware assist (like with Xen and Viridian in the future) is faster than doing the same thing using binary translation (like with ESX). This is not technically accurate as I have discussed in my other article but hey, it's easy to claim that hardware is faster than software.

From this perspective ESX 3i has been one of the best marketing announcements ever in this industry. With relatively little efforts they have achieved a very huge perception that this new thing has completely changed the way things are.

I have already heard some people referring to this as the next step towards Unix-like virtualization (out-of-the-box built-in into the firmware). Well quite frankly I would prefer to have a 2GB hypervisor on 2 hard disk drives but with the right hardware virtualization pieces in place (CPU, Memory, I/O) and in sync with the hypervisor software... rather than the current 32MB hypervisor paired with the immature hardware virtualization support we have now in the industry. Guess which one is closer to a Unix-like virtualization such as the IBM System p servers!?!

But we all know this doesn't matter. Perception is reality and the perception is that a 32MB hypervisor is MUCH better than a 2GB hypervisor. I am not saying that it's not better... it is but I am worried it will be "marketed" as a technical game changer. Which is not. It's just the very natural technology step forward and I am of course happy about that.

In summary I think that life for some VMware sales representatives and VMware partners' sales representatives will be a bit easier (not that was difficult before this announcement).

A tremendous potential point of control

This is by far the most important facet of 3i. While I have always said that in the long run the hypervisor will become a commodity technology, the fact is that for those building virtualization solutions having full control of the hypervisor is very important. From a pure theoretical perspective it is true that you could build your added-value on top of any commodity hypervisor but in reality having the flexibility to own the entire chain end-to-end from the management server (i.e. Virtual Center) all the way to the hypervisor (ESX) is of paramount technical importance. If you own all the pieces you can decide to implement a given piece of functionality at the management server level (as it is the case for VMware DRS) or at the server level (as it is the case for VMware HA).

The concept is very simple: at Palo Alto they know very well that as soon as MS starts shipping their new OS with the integrated hypervisor many "lazy" users will just use that because ... "it's already there". Especially those SMB accounts that do not have the time, money and resources to evaluate whether it would be better to have either one or the other solution... the Microsoft stack is already there, it is good enough so why bother?

To me ESX 3i is a very strategic step made by VMware to anticipate that scenario: bundling the hypervisor with the server (as opposed to bundling it with the OS) should allow them to anticipate Microsoft and sort of leveraging the same laziness of the users that, since there is an hypervisor already "on-board" on the server... they would be more prone to use it instead of something else. This is, in my opinion, the very key strategic value of ESX 3i for VMware: a very powerful point of control.


In conclusion, I didn't certainly want to diminish the value that 3i is bringing into the industry. I am very excited about it because I think it's a step towards the right direction. However I think it is important to clarify some of the rumors and misinformation that have been circulating and that I am sure will circulate even after the details are disclosed.

And by the way yes "point of control" is sometimes perceived as a negative thing, which is, because it basically means that someone is forcing you to do certain things that perhaps you wouldn't have done if you had (to think about) a choice. Now 3i is not at that extreme point but certainly it turns ESX into something more appealing (or convenient if you will) for users that would have chosen other technologies instead. After all, there have always been and there will always be points of control as long as there will be vendors on this planet. They all want to control the market even though we need to understand that there are good practices and bad practices to do that and achieve "control status". I wouldn't personally look at 3i as a brute force strategy to lock in customers if you are wondering.