There are actually two kernels running on an ESX server with the hardware divided between them. The Linux kernel gets some CPU resources, 256 MB RAM (administrator defined), 1 SCSI controller, and one NIC. The VMkernel gets everything else. When you configure the Startup Config in the ESX MUI, you are essentially dividing the hardware between the two kernels. The Linux kernel is responsible for administration and bootstrapping the VMkernel. It is similar to DOS on a NetWare server. The Linux kernel starts first and then it starts the VMkernel. The administration website runs on the Linux kernel. All of the VMs run on the VMkernel. The VMkernel was written from scratch and is very small (couple hundred thousand lines of code, I think). The VMkernel is designed to allow the virtual machines almost direct access to the hardware for CPU and Memory (SCSI and NIC are emulated). CPU access by the virtual machines is scheduled by the VMkernel, not the Linux kernel. _____ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pitsch Sent: Sunday, October 30, 2005 8:11 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: VMWare ESX does equal linux because if it wasn't for the fact that they could hook deeper into the kernel (or whatever) the performance difference between GSX and ESX would be almost nothing. Now you could argue that any open source OS would accomplish the same thing but they chose linux. The VM engine goes through linux to access the hardware. Now I admit, I may be completely wrong but that's how it's been explained to me by VMWare and others. I just can't see anyone recreating the wheel (OS). Otherwise, they would have done exaclty the same thing with GSX. Jeff On 10/28/05, Chris Fraser <chrisfraser@xxxxxxxxxx> wrote: Ya sure but the fact is that ESX does not use the Linux kernel as it's virtualization engine. ESX != Linux. It uses a modified Linux VM for the management interface. Simple as that. If it wasn't for the Apple II or TRS 80 or Commodore 64 or whatever then none of this would be possible :) Jeff Pitsch wrote: > If it wasn't for the linux kernel then none of it would be possible. > > On 10/28/05, *Chris Fraser* <chrisfraser@xxxxxxxxxx > <mailto:chrisfraser@xxxxxxxxxx>> wrote: > > ESX will always have better performance because the VMkernel (not linux > kernel) has full control to manage all hardware resources and doesn't > have to pass request through an OS layer (like GSX). > > Single proc is definitely the way to go on almost all VMs. I'm still > puzzled at the reasoning behind announcing 4-way SMP, esp since it will > benefit maybe %1 of VMs. > > Best Practices Using VMware Virtual SMP > http://www.vmware.com/pdf/vsmp_best_practices.pdf > > ESX Server Architecture and Performance Implications > http://www.vmware.com/pdf/esx2_performance_implications.pdf > > ESX Performance Tips and Tricks > http://www.vmware.com/pdf/esx_performance_tips_tricks.pdf > > Reference & Planning for Virtualizing Citrix > http://www.vmware.com/pdf/esx_citrix.pdf > > Reference and Capacity Planning with Citrix Presentation Server (for ESX > Server 2) > http://www.vmware.com/pdf/esx2_citrix_planning.pdf > > > > Jeff Pitsch wrote: > > ESX will always have better performance than GSX because ESX is tied > > more closesly to the linux kernel. GSX is strictly a service and > > doesn't tie deeply into the OS at all. > > > > Jeff > > > > > > On 10/28/05, *Jon D* <rekcahpmip@xxxxxxxxx > <mailto:rekcahpmip@xxxxxxxxx> > <mailto:rekcahpmip@xxxxxxxxx> > > <mailto:rekcahpmip@xxxxxxxxx <mailto: rekcahpmip@xxxxxxxxx > <mailto:rekcahpmip@xxxxxxxxx> >>> wrote: > > > > I run citrix in VMware GSX, and I have an identical physical > citrix > > box. Both production. > > > > I wish I would have put it in ESX with SMP because the citrix box > > can only use 1 processor which isnt good(even with GSX dual > > processor license). > > > > I would say VMWare burns 20-30% of the resources(the physical can > > probably handle 20-30% more connections). > > > > The performance problems I see is the physical disk, and > mainly the > > processor. 1 3Ghz processor is only good for maybe 23-25 > processes. > > > > Overall I do like it though. If my manager messes up the virtual > > citrix server I just revert it to the last snapshot and its > fixed. > > If he messes up the physical one, I've got a a solid week of > redoing > > it ahead of me. > > > > > > > > -Jon- > > > > > > > > > > . > > > > > > -- > > Check out my eBay auctions > (http://search.ebay.com/_W0QQsassZchrisfraser1111QQhtZ-1) > and my GEMM store ( http://cfraser1111.gemm.com) > > > ******************************************************** > This Weeks Sponsor: Cesura, Inc. > Know about Citrix end-user slowdowns before they know. > Know the probable cause, immediately. > Know it all now with this free white paper. > http://www.cesurasolutions.com/landing/WPBCForCitrix.htm?mc=WETBCC > ******************************************************** > Useful Thin Client Computing Links are available at: > http://thin.net/links.cfm > ThinWiki community - Excellent SBC Search Capabilities! > http://www.thinwiki.com > *********************************************************** > For Archives, to Unsubscribe, Subscribe or > set Digest or Vacation mode use the below link: > http://thin.net/citrixlist.cfm > > -- Check out my eBay auctions (http://search.ebay.com/_W0QQsassZchrisfraser1111QQhtZ-1 ) and my GEMM store (http://cfraser1111.gemm.com) ******************************************************** This Weeks Sponsor: Cesura, Inc. Know about Citrix end-user slowdowns before they know. Know the probable cause, immediately. Know it all now with this free white paper. http://www.cesurasolutions.com/landing/WPBCForCitrix.htm?mc=WETBCC ******************************************************** Useful Thin Client Computing Links are available at: http://thin.net/links.cfm ThinWiki community - Excellent SBC Search Capabilities! http://www.thinwiki.com *********************************************************** For Archives, to Unsubscribe, Subscribe or set Digest or Vacation mode use the below link: http://thin.net/citrixlist.cfm