VMware Communities: Message List - What kernel is ESX based on

Re: What kernel is ESX based on

Mike_Laverick — Tue, 20 Sep 2005 02:08:16 GMT

It's at the bottom of this link:

http://www.vmware.com/company/leadership.html

Thanks George...

Armed with the co-founders names and SimOS and Disco as search strings I've been able to find some of their acedemic papers online...

Regards
Mike Laverick
RTFM Education - VMware

Re: What kernel is ESX based on

GeorgeS — Mon, 19 Sep 2005 19:49:10 GMT

It's at the bottom of this link:

http://www.vmware.com/company/leadership.html

Re: What kernel is ESX based on

jan_av — Mon, 19 Sep 2005 19:45:41 GMT

For reference, I've heard the VMKernel has a Linux compatibility layer. This allows VMware to take existing (tried and tested) Linux drivers and tweak them for the VMKernel to save them having to rewrite drivers from the bottom up.

Cheers, Jan

Re: What kernel is ESX based on

DougBaer — Mon, 19 Sep 2005 19:42:04 GMT

Thanks for the info, George... probably the first bit of actual information in this thread

Re: What kernel is ESX based on

Mike_Laverick — Mon, 19 Sep 2005 18:09:46 GMT

OK, this topic has taken some interesting twists, but
piqued my interest to look into it a little further.
Ken got back with the most interesting answer here.

VMware co-founders Rosenblum, Bugnion and Devine were
all involved in three main Stanford comp science
projects named Hive, SimOS and Disco. All of these
were written to work on a Stanford hardware project,
the Flash multiprocessor, based on a MIPS Risc
Processor.

The last Co-Founder, Wang, is recognized as providing
"contributions to the development of Berkeley UNIX".

All this information is pretty much right off the
VMware web page with some supplements from Stanford's
CS Dept documents.

This would lead me to conclude that in order to build
ESX, it wouldn't take much for the design concpets of
SimOS and Disco to be rewritten for x86 architecture
and may have borrowed largely from what was then the
only 'relatively free' OS code that ran on x86,
Berkely UNIX. The relative commonality between BSD
Unix and Linux drivers probably is why ports from
Linux drivers are 'relatively simpler' to execute, I
don't think that it is 'trivial' however or the HCL
wouldn't be quite so limited.

Thanks for this background. Where did you read this background come from on VMware's web-pages - can you give us a link?

Regards
Mike Laverick
RTFM Education - VMware

Re: What kernel is ESX based on

Mike_Laverick — Mon, 19 Sep 2005 18:02:14 GMT

Hi blackd

As others have said, the core ESX kernel (vmkernel)
is proprietary in-house patent/patent-pending
technology. I think I am right in saying that they
do use linux drivers for some hardware (Qlogic driver
comes to mind).

The CoS is called VMnix and is based on an early
version of RedHat linux, seriously cut down, hardened
and tweaked to run on-top of the vmkernel. The CoS
is used to boot loader for the vmkernel.

I would have thought the Linux driver you might be seeing the COS driver to access the Qlogic card. VMware have to write their own drivers for their own kernel. Hence the very restrictive HCL for ESX, as they don't have the dollars that Microsoft has to support Nvidea graphics cards. :-D

I wouldn't describe the COS as cut down or hardened. There apparently alot unneccassary packages on the ESX CD which are copied across which might not be regarded as neccesaary. From a hardening point of view - whilst high security is used (which allows only SSH/SSL comms) the default settings still allow direct to login directly as root - rather login and then enforcing su - for traceablity. So, people still to this day go about disabling and modifying the COS to make it harder...

Regards
Mike Laverick
RTFM Education - VMware

ps remember 3.1.1 was just a gui front-end to DOS. I heard the vmkernel is based on text-mode version of OS/2. Its either that or based on the SCO kernel. The big question is - will they sue VMware? :-D

Re: What kernel is ESX based on

GeorgeS — Mon, 19 Sep 2005 17:46:24 GMT

OK, this topic has taken some interesting twists, but piqued my interest to look into it a little further. Ken got back with the most interesting answer here.

VMware co-founders Rosenblum, Bugnion and Devine were all involved in three main Stanford comp science projects named Hive, SimOS and Disco. All of these were written to work on a Stanford hardware project, the Flash multiprocessor, based on a MIPS Risc Processor.

The last Co-Founder, Wang, is recognized as providing "contributions to the development of Berkeley UNIX".

All this information is pretty much right off the VMware web page with some supplements from Stanford's CS Dept documents.

This would lead me to conclude that in order to build ESX, it wouldn't take much for the design concpets of SimOS and Disco to be rewritten for x86 architecture and may have borrowed largely from what was then the only 'relatively free' OS code that ran on x86, Berkely UNIX. The relative commonality between BSD Unix and Linux drivers probably is why ports from Linux drivers are 'relatively simpler' to execute, I don't think that it is 'trivial' however or the HCL wouldn't be quite so limited.

Re: What kernel is ESX based on

PepeVM — Mon, 19 Sep 2005 16:31:26 GMT

Great!!!

Re: What kernel is ESX based on

dpomeroy — Mon, 19 Sep 2005 16:28:03 GMT

Windows 3.1.1 is what I heard.

Re: What kernel is ESX based on

graemer957 — Mon, 19 Sep 2005 16:19:53 GMT

Hi blackd

As others have said, the core ESX kernel (vmkernel) is proprietary in-house patent/patent-pending technology. I think I am right in saying that they do use linux drivers for some hardware (Qlogic driver comes to mind).

The CoS is called VMnix and is based on an early version of RedHat linux, seriously cut down, hardened and tweaked to run on-top of the vmkernel. The CoS is used to boot loader for the vmkernel.

G

Re: What kernel is ESX based on

GeorgeS — Mon, 19 Sep 2005 16:11:03 GMT

Not really a Windows feature, but a 32-bit x86 architecture one. 4GB is the max memory addressable in 32-bit w/o using page translation.

Re: What kernel is ESX based on

PepeVM — Mon, 19 Sep 2005 16:08:47 GMT

Sounds awfully hard to believe... Based on the
requirements of the vmkernel (it's a THIN layer), I'd
imagine it would be closer to DOS than ANY flavor of
Windows.

That's why you can manage only 3,6Gbyte per VM and no more...
In W98SE more than 4Gbyte allocation is granted

Re: What kernel is ESX based on

Mike_Laverick — Mon, 19 Sep 2005 15:52:31 GMT

I saw a presentation that talk about the root kernel
that ESX is based on, it was a strange name, does
anyone know what it is?
I know the console is based on a redhat guest, but
I'm looking for the CORE ESX.
Thanks.

As others have said the vmkernel is separate from the linux kernel which makes up the Service Console (or Console OS - COS as others call it)

VMware courseware in the past has explictly stated that the vmkernal is NOT linux - although it still appears to be an oft repeated urban/forum myth...

Regards
Mike Laverick
RTFM Education - VMware

Re: What kernel is ESX based on

jasonboche — Mon, 19 Sep 2005 15:35:03 GMT

I've heard it is based on Windows 98 first edition.
In fact ESX 3.0 will be based on W98SE!!!

That must be NDA because I've never heard that before.

Message was edited by: jasonboche

I'll have what he's having \^^^^^

Re: What kernel is ESX based on

DougBaer — Mon, 19 Sep 2005 15:48:13 GMT

Sounds awfully hard to believe... Based on the requirements of the vmkernel (it's a THIN layer), I'd imagine it would be closer to DOS than ANY flavor of Windows.

BSD would be a MUCH better guess, I'd imagine, but probably just for the basis. It seems to be that it would be more efficient to start completely from scratch.

Re: What kernel is ESX based on

PepeVM — Mon, 19 Sep 2005 15:29:54 GMT

I've heard it is based on Windows 98 first edition. In fact ESX 3.0 will be based on W98SE!!!

Re: What kernel is ESX based on

GeorgeS — Mon, 19 Sep 2005 15:01:33 GMT

Rumor has it that the base code for the kernel started with BSD Unix. It is so highly customized at this point complete with a lot of patented technologies developed as a University project at Stanford that I doubt they will every go back to that base build again.

Re: What kernel is ESX based on

Ken.Cline — Mon, 19 Sep 2005 14:53:47 GMT

How abou VMnix?

That's what they call the COS, a.k.a. the service console, a.k.a. the management interface, a.k.a. ....

Re: What kernel is ESX based on

dominic7 — Mon, 19 Sep 2005 14:52:34 GMT

How abou VMnix?

Re: What kernel is ESX based on

DougBaer — Mon, 19 Sep 2005 14:51:12 GMT

You may have heard the term 'hypervisor', but that's a generic term for the management layer between the hardware and the VMs...

Re: What kernel is ESX based on

Ken.Cline — Mon, 19 Sep 2005 14:49:07 GMT

The vmkernel is a 100% proprietary piece of code developed by VMware. The concepts were derived from some early projects including Disco and cellular Disco...

What kernel is ESX based on

blackd — Mon, 19 Sep 2005 14:46:57 GMT

I saw a presentation that talk about the root kernel that ESX is based on, it was a strange name, does anyone know what it is?
I know the console is based on a redhat guest, but I'm looking for the CORE ESX.
Thanks.