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Nando84
14-May-2012, 17:41
Hi all,

I would like to know which is the best way to implement a virtualized Windows Server 2008 R2 server on SLES 11.

Best regards,
Fernando

Jim Henderson
14-May-2012, 18:06
On Mon, 14 May 2012 16:44:01 +0000, Nando84 wrote:

> I would like to know which is the best way to implement a virtualized
> Windows Server 2008 R2 server on SLES 11.

This description doesn't really give us enough to go on. What is the
intended use, and what options are you considering?

There are lots of options for implementing a virtualized system - and
"best" often depends on the use case and specific needs.

Jim
--
Jim Henderson, CNA6, CDE, CNI, LPIC-1, CLA10, CLP10
Novell Knowledge Partner

Magic31
14-May-2012, 18:34
Hi all,

I would like to know which is the best way to implement a virtualized Windows Server 2008 R2 server on SLES 11.

Best regards,
Fernando

Short answer: If I'd be setting up a new server for this, I'd probably be looking at SLES 11 SP2 64bit as KVM host, then run the Windows 2008 R2 server as a guest on that.

Talking Xen vs KVM, Xen is stronger and preforms much faster when looking primarily at virtualising Linux guests that support paravirtualization

From what I've been reading -need to get around to testing this myself- Windows performs and scales better under KVM (using a recent kernel and KVM implementation) vs Xen.
As KVM is also maintained in the Linux kernel (vs the separate kernel SLES XEN still requires) and the attention KVM is getting, it also seems the wiser choice.

Some more info and specifics on what you are virtualizing on what type of hardware will get you more detailed answers :) ...if that is also what you are looking for.

Cheers,
Willem

enovaklbank
16-May-2012, 14:38
I agree with you on your advice and you are generally right. KVM has probably better paravirtualised drivers as well.



As KVM is also maintained in the Linux kernel (vs the separate kernel SLES XEN still requires)


But this one is not longer true, Xen is in the upstream since 2.6.~39 (parts of it sooner - .37, some minor parts later, but they're in). As SP2 runs kernel 3.0, this is no longer a concern.

I just like to point things like these out, because they need years to change in the public knowledge anyway - popular error.

Jim Henderson
17-May-2012, 02:00
On Wed, 16 May 2012 18:18:28 +0000, enovaklbank wrote:

> Magic31;4580 Wrote:
>>
>> As KVM is also maintained in the Linux kernel (vs the separate kernel
>> SLES XEN still requires)
>>
>>
> But this one is not longer true, Xen is in the upstream since 2.6.~39
> (parts of it sooner - .37, some minor parts later, but they're in). As
> SP2 runs kernel 3.0, this is no longer a concern.

I think Willem's point, though, is that there is a stock kernel and then
there's a XEN kernel. It's not part of the default kernel, so you need
to boot a different kernel than the default kernel to get XEN running.

I'm pretty sure he wasn't saying that XEN isn't part of the Linux kernel,
just that there's two different kernel configs used.

Jim
--
Jim Henderson, CNA6, CDE, CNI, LPIC-1, CLA10, CLP10
Novell Knowledge Partner

Magic31
17-May-2012, 07:23
I agree with you on your advice and you are generally right. KVM has probably better paravirtualised drivers as well.



But this one is not longer true, Xen is in the upstream since 2.6.~39 (parts of it sooner - .37, some minor parts later, but they're in). As SP2 runs kernel 3.0, this is no longer a concern.

I just like to point things like these out, because they need years to change in the public knowledge anyway - popular error.

Yes, Xen has been added (big parts of it) to the Linux kernel. So there is progress there :)

The thing is that not all needed parts of Xen (mainly certain acceleration and hardware support aspects to say it very roughly) has not all been added (yet...).

Hence SLES SP2 Xen still has to run on a separate kernel build that is still separately maintained. That's where I see KVM has the edge in it's development and maturing cycle (which at the same time can prove is a potential danger to watch for as regressions in the main kernel might affect KVM workings more - but that's going into a misty topic).

When I first heard Xen was finally really being adopted and integrated into the mainstream Linux kernel, I was very excited.... a direct picture that popped up in my head was that of Linux clusters doing KVM, Xen, LCX and all this great stuff simultaneously.
As processing power and hardware capabilities of higher end servers these days can handle great loads, it's something I'm still rooting/hoping for in the next couple of years.

Put some nice management tools on top of that.... I like the ideas that stem from that. :)

Back to the topic in the now, that's one thing I love about the forums... picking up on what others are learing/facing/thier views/etc, etc.... It's no world (any longer) where one has "the knowledge", and it's *great* to be able to share and learn.


As far as the drivers go KVM vs XEN on a SLES 11 SP2 host.... it's about even as I gather it, but also depends on the guest OS one is running. From what I've seen, Xen still wins greatly when running SLES or OES on SLES Xen. Windows guests on the other hand.. seems to be KVM is a winner there... also when looking at how it scales (how many guests you can run on the host without seeing signs of slowdown).

Still lots to test here myself! :)


Cheers,
Willem

Magic31
17-May-2012, 07:26
I think Willem's point, though, is that there is a stock kernel and then
there's a XEN kernel. It's not part of the default kernel, so you need
to boot a different kernel than the default kernel to get XEN running.


Thanks Jim, indeed... that was my point. :)

Cheers,
Willem

Nando84
17-May-2012, 15:36
Hi all,

First of all, I would like to thanks all of you for all the help.

Second, I apologise for the little information but I am new in the Linux field.

I am not considering any options here. I am working with a enterprise that has a SLES 11 server with Xen as the virtualization plataform. The hardware of this server is compatible with 64 bits OS and the CPU is a Intel Xeon with Intel Virtualization Technology (Intel-VT). The storage is compound of two SATA II HDD with RAID 1 configured on them. This server has two Windows Server 2008 R2 virtualized servers.

Recently I started to search for some info about SLES and Xen because the Windows servers are working too slow and also have a driver issue (The servers are not paravirtualized). But like I said at the begining, I am not a Linux user so I decided to post a question here first. I found that there is a driver pack called "SUSE Linux Enterprise Virtual Machine Driver Pack 2.0" but I don't know if we can implement this on a server that is not paravirtualized. Or if it helps somehow in this case.

I hope you understand me.

Thanks in advance,
Fernando

Jim Henderson
18-May-2012, 00:32
On Thu, 17 May 2012 14:44:01 +0000, Nando84 wrote:

> I hope you understand me.

That helps a lot, yes. I'm not well-versed in XEN, so I'll have to defer
to someone else's expertise on the driver plugin.

One thing, though, that's key to VM performance is memory utilization -
you don't mention how much memory is in the host, nor how much is
allocated to each of the guests. That might be important information to
include.

Also, if the guest machines are used for CPU-intensive tasks, then
virtualization (of any kind) may not be an appropriate implementation.
If you can assign specific cores to the VM, then at least they won't
interfere with each other, but HPC and Virtualization generally don't go
together because the HPC requirements compete with he resource sharing
requirements.

Jim
--
Jim Henderson, CNA6, CDE, CNI, LPIC-1, CLA10, CLP10
Novell Knowledge Partner

Magic31
18-May-2012, 06:50
I found that there is a driver pack called "SUSE Linux Enterprise Virtual Machine Driver Pack 2.0" but I don't know if we can implement this on a server that is not paravirtualized.
Fernando

Hi Fernando,

Yes, that driver pack will help. Windows machines are by default always running fully virtualized. This just means the guest machine itself is not aware it is running as virtual machine and does nothing special to optimize workings with it's given hardware (disk, network, memory mainly) in a virtual environment. All the work is done by the hypervisor/host.

Installing these drivers will bring some extra awareness to the Windows guest and opens a more direct communication channel to the hardware devices (disk and network mainly) + adds some extra management options and specific acpi support. It should boost performance. Next to installing these drivers, also make sure you are running with the latest patches/support pack applied on the Xen host (SLES 11 SP1+ all patches at least).

The nice thing about the version 2.0 VMDP (Virtual Machine Driver Pack) is that is has drivers needed for both Xen as also KVM. If you have options to install SLES 11 SP2 (64bit version) as hypervisor host (on a test desktop op server with Intel-VT or AMD-V support) - you can test the performance of a same VM running Xen or KVM.

Hope that helps,
Willem

enovaklbank
18-May-2012, 12:18
On Wed, 16 May 2012 18:18:28 +0000, enovaklbank wrote:
I think Willem's point, though, is that there is a stock kernel and then
there's a XEN kernel. It's not part of the default kernel, so you need
to boot a different kernel than the default kernel to get XEN running.

I'm pretty sure he wasn't saying that XEN isn't part of the Linux kernel,
just that there's two different kernel configs used.


Ah, ok, then it's true :)
I don't think it'll be possible to integrate the two into one in the future - the Xen hypervisor concept is different than the idea of running KVM as a module - but aside from nvidia drivers being incompatible, I don't see a problem with running a Xen kernel primarily...

Nando84
18-May-2012, 13:28
Hi Jim,

I forgot the memory information. The host server has 32 GB of DDR3 ECC RAM with two guest servers in it. One guest has 2 GB of memory and the other 24 GB.

These machines are not for HPC, one is an Active Directory server and the other runs an ERP solution that does not use much CPU.

Best regards,
Fernando

Nando84
18-May-2012, 14:39
Hi Willem,

This information helps me a lot!

I didnīt know well how this driver worked but now is very clear.

Thanks a lot all of you!!

Best regards,
Fernando