Greetings,
is Xen considered as a bare-metal virtualizing solution that is equivalent to ESXi ? or it can be used as VMWare Workstation, in which it installs on a Host OS then you can create VMs inside the running Hosting machine?
Thanks
Kind of yes to both. Xen is a kernel, so it is a hypervisor like ESXi
that focuses on performance which is why it is used by things like Amazon
Web Services (AWS) and a bunch of other virtual hosting (cloud) providers.
Unlike ESXi, you have a full Linux system around it so you can do all of
the things you are used to on the box like you can in a normal Linux
environment. Huge plus, IMO, since ESXi is something of a black box, and
accessing it other than through virtual center is basically a sin
deserving capital punishment (support voided).
Xen, though, is a different kernel from your standard Linux kernel, so
SOME things are definitely different. Want to play fancy 3D games on your
laptop using the Xen kernel? Probably won’t work as well as it would with
the standard Linux kernel and extra third-party video drivers. Want to
run KVM VMs as well, which are now part of the mainline Linux kernel?
Probably not going to work, as I think the two are currently mutually
exclusive (check before quoting me on that). For 99% of things, it’s the
same, but this is a separate kernel, so there are some very low-level
differences that you’ll likely, on a server, never notice.
For additional compromise, you have KVM, which is like Xen in that it’s
part of the kernel, but unlike it in that it is part of the
mainline/default/standard Linux kernel, so more normal things work. Will
you actually care about 3D game performance on a VM host? Probably not,
but just in case you do, KVM is probably a better option. With that said,
as these are different kernels you could boot back and forth between the
standard kernel and the Xen kernel, but that just seems weird to me. Both
solutions are great, flexible, powerful. Using KVM also means you could
do other lighter-weight virtualization (OS vs. machine virtualization)
which is a huge advantage if you get into that, since OS virtualization is
much lighter-weight than machine virtualization (no need to virtualize
hardware as much) and is done with “containers”, using LXC. If you have
seen recent references to the Docker project, those are related too.
–
Good luck.
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Thanks for your reply.
It can’t be yes for both, where originally ESXi is Different than VMWare Workstation, as long as ESXi does not require and OS to be running like VMWare Workstation which installs on top of a functional Host “OS installed”
unless you mean it can be used in two different installations “Xen as Hypervisor like ESXi” and “Xen as VMWare Workstation”. in this case, can you provide the steps to install Xen as “VMWare Workstation”, because I tried to install it “Xen” and it asks to restart in Xen Kernel mode to be able to create/manage virtual machines.
thanks
On 10/24/2014 03:06 PM, jamilsaif wrote:
>
> It can’t be yes for both, where originally ESXi is Different than VMWare
> Workstation, as long as ESXi does not require and OS to be running like
> VMWare Workstation which installs on top of a functional Host “OS
> installed”
Comparing ESXi and Workstation to Xen works in many areas, but like every
comparison, it is imperfect. Unlike Workstation, Xen runs at the kernel
level, as it is the kernel. Unlike ESXi, you can still do things with the
machine besides host VMs, like use Yast to setup things, even VM-related
things, or have a full GUI, etc. Xen is “added” potentially to an
existing system, but you reboot to use that kernel instead of the standard
Linux kernel, but that does not mean you still cannot use the machine as a
workstation. I wouldn’t do it on principle (dedicated VM hosts (as my Xen
boxes all have been) should be dedicated VM hosts, end of story, in my
opinion), but I know people who still do it.
> unless you mean it can be used in two different installations “Xen as
> Hypervisor like ESXi” and “Xen as VMWare Workstation”. in this case, can
> you provide the steps to install Xen as “VMWare Workstation”, because I
> tried to install it “Xen” and it asks to restart in Xen Kernel mode to
> be able to create/manage virtual machines.
Go ahead and reboot into that kernel, and then continue to use the box as
a workstation if you’d like. Most things still work. It’s not an
application like Workstation, but it also does not prevent you from doing
most of everything else with the box, like ESXi. It’s a different beast
entirely.
–
Good luck.
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IMO there is a little bit of confusion here…
When you refer to an application like VMware Workstation and how it differs from “bare metal”
Bare metal typically means that only the basic fundamentals are available to run virtualized Guests. No proper OS is running although typically a “barely there” OS bootstrap is implemented to start, manage and end processes. People generally choose this type of deployment when they
- Want to minimize attack surface
- Minimize complexity
- Conserve machine resources
When more Host functionality is desired, a full OS boots first, and then the User Tools (application) can be invoked. Note that nowadays with paravirtualization the Guests are deployed and run the same whether you’re talking about bare metal installs or deployments with full User Tools installed… Hardware defines the running Guest environments in both cases.
Since I’m not a regular User of Xen, I don’t know if an official Xen bare metal hypervisor is available today, it wasn’t available from its origins up to a year or so ago when I turned my attention elsewhere. I would think by now there would be a movement to create such, but I haven’t heard about it. So, for now I would just recommend that you install Xen in a text-only distro like openSUSE, it’s pretty close although not the same as what you’d get with ESXi and Hyper-V hypervisor. By minimizing installed apps and setting up your FW properly, you should satisfy the objectives using something like ESXi. If you went further and customized a JeOS image, you could maybe even call it a “bare metal Xen hypervisor.”
TSU
please refer to my original question and read thoroughly, “is Xen considered as a bare-metal virtualizing solution that is equivalent to ESXi …”
So, where did you see me writing VMWare workstation is a bare-metal etc…???
With trust
My entire post was in response to how the thread evolved.
You should also have had your question answered in my post… ie. Deploying the Xen in a way equivalent to ESXi.
TSU