Virtualistion questions

[sparkeh]

I had planned to look into the options for virtualising our server next year, but now the server is failing (without being able to be fixed) and I need to bring it forward somewhat. However without putting the research in I am feeling very under-prepared so some advice would be much appreciated.

 

The new plan is to get a new server, run a hypervisor, virtualise the old server (Win 2003) and run it on the new. Then I will get 2008 up and running and migrate to that.

 

First up, which hypervisor? I have looked at Hyper-v, ESX and XenServer.

 

As I understand it, Hyper-v needs 2008 to be installed, which ties up a licence which I would otherwise use to run our new server in the future, but then I believe that it uses 2008's drivers so could offer greater compatibility. XenServer seems to offer a lot more for free though. What are other people running and why did you choose it?

 

Next is how to virtualise the current server. If I went with ESX then I could use VMWare vCenter Converter. How do I virtualise for the other offerings?

 

I am sure there are more questions to come

 

Any help is very much appreciated.

[tmcd35]

Which Hypervisor? There are more answers to this question than their are hypervisors. It's almost a Mac vs PC debate....

 

If you're buying a Windows Server license anyway then Hyper-V is as good as anything - comes free with Windows. If your hardware is compatible then ESXi is a very good and stable system - highly recommended, just check your hardware first. Then there is Xen. Not used it myself. I alway get the feeling it's more Linuxy, others will tell you that you'll never see the Linux host with good management software. Who knows, its an option!

 

Personally I'm tredding down the Hyper-V route purley on the basis that it comes with Windows as standard!

 

Microsoft have a very good physical-to-vhd convertor that will convert live running systems. Just used it for the first time today. IMHO it works better then VMWare Convertor (which I found hit and miss in the past).

 

Again don't know what Xen's offering in but there pretty much as to be a freebie equivalant.

 

In the past I've fallen back on make Ghost/Clonezilla images of the physical hard drive and then imaging the virtual machine in the normal way.

 

Beware with all physical-virtual solution you will have to do a repair install of Windows to get it working again. Also try to avoid doing physical-virtual on a DC unless you have to, it can cause problems (though I have successfully done this in the past).

[sparkeh]

Next is how to virtualise the current server. If I went with ESX then I could use VMWare vCenter Converter. How do I virtualise for the

 

Ok i have found XenConvert now which looks good.

[sparkeh]

Thanks

Yeah its a DC, I didn't realise that meant extra issues.

 

My first thought was to go with Hyper-v but then I find it quite annoying that I need to use a licence to install 2008 just to run the hypervisor, ideally I will run 2008 virtually in the future meaning another licence.

[teejay]

From my experience, ESXi v4 works a dream.

Have tried Citrix Xenserver and although it has more features in the free version I didn't get on with it that well as there are some limitations which for us were a show stopper. The main problems were network link aggregation limited to 2 nics, which wasn't so good for connecting to our SAN, the conversion software for P2V just didn't work with most of our servers, the graphics drivers aren't very good, plus a complete pain to run a linux which isn't one of their limited selection of supported versions.

There are quite a few people who have run XenServer on this forum who are very happy with it, so it may just be our unique circumstances.

Haven't played with Hyper-V, specs just doesn't do what we need it to do.

[teejay]

Thanks

Yeah its a DC, I didn't realise that meant extra issues.

 

My first thought was to go with Hyper-v but then I find it quite annoying that I need to use a licence to install 2008 just to run the hypervisor, ideally I will run 2008 virtually in the future meaning another licence.

 

VMWare converts DC's no problem, have done a few over summer and had no problems at all.

[sparkeh]

plus a complete pain to run a linux which isn't one of their limited selection of supported versions.

 

Hmm yeah good point, I would like to move FOG onto the server as well. Although I do see that there is a download to add linux guest support.

[teejay]

Ok i have found XenConvert now which looks good.

 

Apart from -

You can only convert one hdd at a time and doesn't allow you to queue up conversion jobs.

Tried for 5 days to get server to convert, using the VMWare tools I spent a day playing and then queued up 9 servers over a weekend and came in Monday morning with them all done.

Edited October 27, 2009 by teejay

[teejay]

Hmm yeah good point, I would like to move FOG onto the server as well. Although I do see that there is a download to add linux guest support.

Yes, but you need Xen support compiled into the kernel before you convert. I gave up with trying to get our Ubuntu servers to work with this. A fresh install of Debian using the XenServer linux guest support stuff did work well though.

[sparkeh]

With Hyper-v, I know that you have to have 2008 installed, can you launch Hyper-v on its own, so 2008 isn't using up resources, or does it have to be running?

[ahuxham]

With Hyper-v, I know that you have to have 2008 installed, can you launch Hyper-v on its own, so 2008 isn't using up resources, or does it have to be running?

 

Well

 

Did you know Windows Server 2008 Hyper-V edition is free? More a bare-metal Hypervisor in itself, using less resources, you configure the server via Hyper-V powershell extensions. Very good, and it being free as well is very attractive.

 

ESXi 4 is a dream as well, however vSphere to manage/control is not cheap.

[sparkeh]

Well

 

Did you know Windows Server 2008 Hyper-V edition is free? More a bare-metal Hypervisor in itself, using less resources, you configure the server via Hyper-V powershell extensions. Very good, and it being free as well is very attractive.

 

Right...ok now I am confused again.

 

Free? Doesn't it come with your purchase of 2008?

I have been reading the MS documentation on hyper-v and the installation instructions tell you that you can install the 'server core' to have a minimal installation to run hyper-v or through a full server installation. Therefore I assumed that you had to have 2008 running.

[sparkeh]

Did you know Windows Server 2008 Hyper-V edition is free? More a bare-metal Hypervisor in itself, using less resources, you configure the server via Hyper-V powershell extensions. Very good, and it being free as well is very attractive.

 

Ahhhh! I see now, theres a standalone version!

 

Thanks I get it now

[tmcd35]

Yes there is a free stand-alone(ish) version of Hyper-V. And yes it also comes with 2008 server as standard.

 

One thing to do is check your Windows Licences

 

2008r2 standard = 1 physical server + 1VM server

2008r2 enterprise = 1 physical server + 4VM servers

2008r2 datacenter = 1 physical server + unlimited VM servers.

 

Datacenter is licensed per physical processor in the server (in most cases you need 2 copies per server). Even so Datacenter is a real steel for education. I just paid £180 per copy!

[powdarrmonkey]

sparkeh: linky?

[sparkeh]

sparkeh: linky?

 

Microsoft Hyper-V Server 2008

 

There you go fella.

[theriver]

Hi there.

 

A Windows 2008 Standard licence allows you to run a single virtual instance on top of the OS - so you can install Windows on the box and legitimately virtualise your network server with one single licence.

 

 

Ref:

http://download.microsoft.com/download/E/E/C/EECF5D44-9A88-43D8-AFDB-D2AB82BE035C/Win%20Server%20Lic%20Book%20customer%20hi-res.pdf

 

 

It seems to me that the problems people here have mentioned with virtualising DC's are around using snapshot type features, but it's not something I've paid too much attantion to, so a little more research would be recommended.

[Theblacksheep]

Free? Doesn't it come with your purchase of 2008?

I have been reading the MS documentation on hyper-v and the installation instructions tell you that you can install the 'server core' to have a minimal installation to run hyper-v or through a full server installation. Therefore I assumed that you had to have 2008 running.

 

It does... and its free.... however for windows ontop of it you'll need an enterprise or appropriate CPU datacenter licences. Unless you are running 1 VM, in which standard will work, but that'll be the only windows VM allowed on the box.

 

@tmc35: I've not had to do any windows repairs with VMware converter. Exchange worked straight away and I've not had to do a repair... is this something specific to hyper-v?

[tmcd35]

VMWare converts DC's no problem, have done a few over summer and had no problems at all.

 

Yes I know it can be done, I've done it - just proceed with caution!

 

You'll be take a DC offline for an extended period of time and performing a repair install of Windows on it. It could seriously get out of sync with your live AD and cause all sorts of problems. If at all possible demote the server from a DC first and re-promote to a DC after P2V conversion is complete.

 

P.S.> Did I mention M$'s P2V convertor (free) works on live running systems and is very very fast. The VMWare convertor (last time I used it) had to booted from CD and took an eternity to run through.

[ZeroHour]

Its free as in when you buy your 2008 lic you automatically get the right to run another instance of 2008 virtualised as that extra lic is free. If you buy enterprise you get 4 instances virtualised where as standard edition is only one.

Running 2008 on the bare metal does use resources but the hyperv layer means it only mimimally effects the virtual machine performance. The VM's access the hardware using a direct layer rather then just routing through the OS (but it does still a little)

 

As for converting, I have used SCVMM which is sweeties to license and so far not had a bad image yet or a reinstall. SCVMM works with vmware as well and can coverter multiple drives etc, its really quite nice tbh as well as converting a vm in hyper-v to say esx if you wanted.

[tmcd35]

@tmc35: I've not had to do any windows repairs with VMware converter. Exchange worked straight away and I've not had to do a repair... is this something specific to hyper-v?

 

I think, when the VMWare Convertor works, it puts all the right drivers in place - probably why it takes so long - and so you don't have to do a repair install.

 

With most P2V conversion you have to do a repair install because of the change of hardware between the physical and virtual environments. Without doing it you can get BSOD's and the like.

 

Like I say I found the VMWare Convertor very touch and go as to whether is wanted to run or complete on some hardware. Seemed to be as picky about hardware as ESX is. Grrrr.

[Theblacksheep]

I think, when the VMWare Convertor works, it puts all the right drivers in place - probably why it takes so long - and so you don't have to do a repair install.

 

With most P2V conversion you have to do a repair install because of the change of hardware between the physical and virtual environments. Without doing it you can get BSOD's and the like.

 

Like I say I found the VMWare Convertor very touch and go as to whether is wanted to run or complete on some hardware. Seemed to be as picky about hardware as ESX is. Grrrr.

 

Thanks for the info.

 

Our VMware converstion of exchange03 was done live (converter4 rocks) and took about 6 hours with about 100GB of data and a resizing of the HDs as they were coming over (thanks RM for the 8gb C drive)... I've not personally had any hardware troubles with conversion, just powered on afterwards (removed a few devices) and it worked.

[vikpaw]

sparkeh,

 

i struggle to come to terms with using windows on a nice bit of expensive server kit, but heck we all do it. but, using hyper V just seems to be asking for trouble : basing potentially multiple virtual servers on one bit of hardware all under the auspices of microsoft software. alarm bells ringing anyone?

 

Ric_ is the only xen expert i know, so maybe he can give you some tips, he has SIMS running on it and probably much more. It's too unixy from my understanding.

 

I've been testing VMWare and much prefer it. VMWare server is free to use on Windows but very limited. VMWare Fusion for macs is awesome. We're looking at going for ESXi for our new blade server but to get the best out of it, you have to pay for the management tool.

 

When we researched one of the biggest differences we saw between esx and xen was something to do with memory management and allocating dedicated amounts to each VM.

 

I think Xen would be the best option if i / we had the time to play around with it and learn it well, but we'll most likely go with VMWare as it seems easier to use.

 

The VMWare stuff is free to download and use so you can test it out.

 

As for converting physical to virtual, it's possible, but i had a few problems because i was sending the VM to some kit with rather different hardware to the original machine and it didn't like it. If you are going virtual and it's possible i would recommend starting from scratch and rebuilding the server if it's possible. It's a good excuse for getting rid of any legacy issues you may have.

 

Search the forums there are some very good threads on different bits of kit and the advantages and differences between them. Plenty to take in.

 

Good luck.

[ahuxham]

Ahhhh! I see now, theres a standalone version!

 

Thanks I get it now

 

Yeap, stand-alone version running on a server 2008 core, no need to purchase 2008 at all, totally free product, and I guess Microsofts push toward the market, with Citrix, Sun and VMware offering free solutions.