VMWare ESXi now free

[Thomas Charron]

On 7/29/08, Jeffrey Obrien <JObrien at expertserver.com> wrote:
>>  ESX is actually using a small Linux kernel which then loads VMWare
>> modules which actually perform the virtualization.
> I thought the same for quite some time(VMware server works like that) until I looked into it more and was told by the VMware folks thats not the case(Im still skeptical though, they ARE owned by EMC ;) ).  According to VMware the 'official' process goes like so...
> 1.) Std x86 boot process (POST -> MBR)
> 2.) Grub loads up the vmkernel and initializes the hardware
> 3.) The vmkernel loads up a virtual instance of RHEL 3 U9 (as of 3.5 U2) to act as the service console for administrative purposes.

  That seems counter to their own support documentation, unless of
course they implemented a wrapped around the Linux modules themselves.

  I just went and looked, and indeed, they use the LInux hardware
modules directly, see http://www.vmware.com/pdf/vi35_io_guide.pdf.

"While ESX Server software itself is not derived from Linux, it
includes a Linux compatibility module to allow Linux storage and
networking drivers to be adapted and
recompiled for ESX Server hosts. This enables VMware and VMware
partners to more easily support a wide range of high‐performance
devices and eases the driver
porting effort on the storage and networking device vendors."

  So it's got the arms and legs of Linux, but not the brain..  Interesting..

> The ESX kernel is based on a 2.4 kernel but is not the linux 2.4 kernel.  So just
>because a piece of hardware is supported in the standard 2.4 kernel doesn't mean it
>will work with ESX.  Their drivers are not standard and are customized to work with
>their proprietary kernel.  If you want standard drivers you are better off with XenServer
>which is based on CentOS 5 and uses standard hardware and drivers.

  See the above document, which is where I got the 20 page quote from.
 Yes, they are 'forked' in a manner of speaking.

-- 
-- Thomas