Which Hypervisor?

[Gimli_]

Ok forumites, to myself, from myself (cause I worked so hard this year) I am buying a home/test/play server. Intel s5000vsasatar board with two xeon 5420 processors and 8 gig ram. I will run a variety of vm's with mix of windows and linux operating systems. Mostly servers and maybe some desktop virtualization as well.

The question is which hypervisor should I use. I have done some research and have found there are so many options, frankly I can't choose. I have to choose between (all free)
- VMware ESXI
- Microsoft Hyper-V server 2008
- Ubuntu server with KVM
- Proxmox (basically a cut down debian OS with KVM and neat management interface)
- Sun xVM server
- Xen server

Do you have experience with any of these, what are the pros and cons of the different products?

Your help and insights appreciated

 

[Conradl]

Depends on what you want to do. Will focus on the so called "Big 3", VMWare (ESX), Citrix (XenServer) and MS (HyperV). Firstly, a virtual Host will be useless, unless you have some means of connecting to it, so keep in mind that you will need another PC handy as a client.

Secondly, hardware requirements: XenServer/HyperV requires a VT enabled processor to start Windows based machines, but will run on an IDE/SATA disk. VMWare requires a SCSI or Fibre Channel disk; but will run on a non VT processor. VMware also requires a SQL database machine, and a machine for the management software. Also most functionality on all products requires some sort of shared storage and two hosts.

In addition, XenServer is a free, fully enabled product; unlike ESXi which has limited functionality and HyperV which just has limited functionality. XenServer also supports both XVA and VHD file formats, and requires no additional licenses for the management software (XenCenter is free).

One option (what I do in my own labs), is to install host based VM software, on top of Windows, and then create 2 XenServer VMs (Hosts), and a third VM for shared storage (openfiler). This will allow you to run multiple Linux machines; unfortunately you will not be able to run windows since the VM software BIOS does not support VT.

Summary (performance of the various products is all the same, and not really relevant). Note that there are additional differences not mentioned here because I don't think they are relevant to your needs:-

Citrix XenServer
Pros: Fully functional, free software. Works on a single host. Supports VHD and XVA.
Cons: Does not support as many appliances as VMWare. Requires VT processor.

VMWare ESXi
Pros: Large number of appliances.
Cons: Limited functionality in ESXi, requires SCSI/FC disks, needs a SQL database/management server.

MS HyperV (you really should be using one of the two above!)

 

[Gimli_]

Thanks for the info, but I need to question the bit on VMware.
- I have not seen in all documentation that I read that it requires a SQL database server
- That it requires SCSI (I have seen it boot from USB for that matter)

I will only have one vmhost and that is the server I am buying now and it has SATA only disks. I have another machine and a laptop with network to be able to access/manage it. I don't plan a bigger installation with live migration between hosts, and for that I suppose you need the additional management server and software. The Xeon E5420 is a VT processor so no problems there.

I have not read a lot about Xen Server but maybe I will do because it looks like you are quite happy with the choice. Question about Xen, will it allow you to assign USB port as a resource for your guest?

I have been quite impressed with proxmox from their web demos etc. but I am not a big debian fundi so will probably avoid it, although it seems that you can do everything you need via their webgui. xVM also looks very polished

 

[Conradl]

Thanks for the info, but I need to question the bit on VMware.
- I have not seen in all documentation that I read that it requires a SQL database server
- That it requires SCSI (I have seen it boot from USB for that matter)

The SQL database, as you mentioned below is used for the advanced features, DR, live migration etc. I see that the latest version of ESXi does run on SATA; ESX3 only worked on SCSI and I assumed that it would be the same with ESXi....

I have not read a lot about Xen Server but maybe I will do because it looks like you are quite happy with the choice. Question about Xen, will it allow you to assign USB port as a resource for your guest?

Yes you have an option to load a USB drive as an SR. I use XenServer, because its free and part of the Citrix suite which we support (and its a great product that I trust). My partner is more experienced with VMWare - but even he agrees that XenServer is ideal for most situations. I'm busy downloading Xen 5.5 if you want to get a copy (although its small at around 500MB if you want to download it).

I have been quite impressed with proxmox from their web demos etc. but I am not a big debian fundi so will probably avoid it, although it seems that you can do everything you need via their webgui. xVM also looks very polished

We are constantly evaluating new products; its damn hard to keep up, especially with the explosion of Virtualisation software!

You mention that you want to run Virtual Dekstops? You should check out Citrix XenDesktop - its like VMWare VDI, but uses the superior ICA (not RDP), as a display protocol. Its also free for 10 desktops or less....

 

[Gimli_]

I'm busy downloading Xen 5.5 if you want to get a copy (although its small at around 500MB if you want to download it).

Just downloaded it as well, I have had a look at the documentation and video tutorials on their site and must say that it also looks like a good product. I noticed that the installer looks like a Linux one so I assume this is based on a linux OS of some sort.

You should check out Citrix XenDesktop - its like VMWare VDI, but uses the superior ICA (not RDP), as a display protocol. Its also free for 10 desktops or less....

This is good news, us XenDesktop like the 'Citrix Client' I know from a few years back? I mean, do you install it on a PC and then access the virtualised desktop on the server? If so how good is graphics performance using this client, and how do you improve graphics performance of virtualized desktops, does the processor do all the graphics processing?

 

[Gimli_]

By the way, I read that Xen Server only supports 4 concurrent VM guests and thereafter you need a license? Is this true and where do you get the license, do you have to purchase it?

 

[Conradl]

Just downloaded it as well, I have had a look at the documentation and video tutorials on their site and must say that it also looks like a good product. I noticed that the installer looks like a Linux one so I assume this is based on a linux OS of some sort.

That is correct. In 2007 Citrix acquired XenSource, and then created Citrix Xenserver. So, Citrix XenServer is a commercial (and free) product built on the Xen open source hypervisor.

This is good news, us XenDesktop like the 'Citrix Client' I know from a few years back? I mean, do you install it on a PC and then access the virtualised desktop on the server? If so how good is graphics performance using this client, and how do you improve graphics performance of virtualized desktops, does the processor do all the graphics processing?

XenDesktop is similar to the product that you describe (which is Presentation Server, now XenApp). With XenApp you install applications on a server and allow multiple users to access applications on that server, i.e. the server is shared.

With XenDesktop, you create a Windows XP VM (running on XenServer), and then give a user access to the desktop through ICA, i.e. each user has their own virtual PC, except now its hosted and running on a server.

Graphics performance is good for business applications, and certain 3d appliations (not gaming). The ICA client has the ability to run certain content using local (client) resources. If for example you open a video clip on a XenDesktop, it will stream the video to your PC and use local resources to view the content (as apposed to trying to refresh the entire desktop using the ICA protocol). It is much better than RDP!

By the way, I read that Xen Server only supports 4 concurrent VM guests and thereafter you need a license? Is this true and where do you get the license, do you have to purchase it?

This was true for previous versions of XenServer. The current version has NO license limitations in terms of Memory, CPU or number of VMs. You do require a license, you can download it from Citrix.com, at the same place you downloaded the images. Also download XenCentre to manage the Hosts/Vms