virtualbox.org

Hey all,

I'm in the process of getting rid of Windows in my company. The work is done on all servers, and on 1/3 of the desktops. The remaining 2/3 are still running Windows because of a legacy application which we simply cannot get to work with WINE (it's a telephony related application, with lots of old TAPI stuff).

So I've been thinking about creating a server with a bunch of Windows XP guests. These can then be accessed using VRDP, when the legacy application is needed.

Initial tests show that this approach works pretty well. Sure, the interface is a bit laggy compared to having the app running locally, but it's not really a huge problem. The application itself is not very demanding (it runs fine on an Intel Atom platform with 512MB RAM). Most IO is on a bunch of network drives, so there's hardly any activity on the "local" Windows c: drive.

I will probably need to have ~20 Windows XP guests running simultaneosly. What kind of host would be the best fit for such a setup? Linux? OpenSolaris? How much CPU/RAM? Will I need to look into SSD's, or is a bunch of fast SATA drives good enough? What would be a good method of installing? Should I run headless, or?

Any and all advice on such a setup is much appreciated.

Regards,
Thomas

This is not a VM scenario.

Better think about a windows terminal server / Citrix.

It most certainly is a suitable scenario for VMs.

Host OS depends on what you are most comfortable with. Linux or Solaris are good candidates. With 20 VMs you'd want at least a dual quad-core CPU, but it depends on the average cpu load. For RAM it's simple math. 20 x 512 = 10G, so get at least 16 GB. It all depends on how many resources an average VM needs; cpu and memory wise. If the harddisk IO requirements are not high, then I don't see the need for expensive SSD drives.

It's a bit hard to give you an exact answer though. With only RDP clients you would of course run all VMs in headless mode.

sandervl wrote:It most certainly is a suitable scenario for VMs.

Host OS depends on what you are most comfortable with. Linux or Solaris are good candidates. With 20 VMs you'd want at least a dual quad-core CPU, but it depends on the average cpu load. For RAM it's simple math. 20 x 512 = 10G, so get at least 16 GB. It all depends on how many resources an average VM needs; cpu and memory wise. If the harddisk IO requirements are not high, then I don't see the need for expensive SSD drives.

It's a bit hard to give you an exact answer though. With only RDP clients you would of course run all VMs in headless mode.

Thank you.

It's good to know that it's a viable solution. I will probably settle on 2 servers, each with 20 VMs installed but only 10 VMs running. That way I have some cheap/simple redundancy in case one of the servers crash.

With that amount of RAM required, I will have to use a 64bit host, right?

I'm very familiar with Slackware, so I will probably go with that as the host OS, unless of course there are some benefits from going with an OpenSolaris/VirtualBox combination?

Regards,
Thomas

ThomasLocke wrote: It's good to know that it's a viable solution. I will probably settle on 2 servers, each with 20 VMs installed but only 10 VMs running. That way I have some cheap/simple redundancy in case one of the servers crash.

With that amount of RAM required, I will have to use a 64bit host, right?

In theory a 32 bits host with PAE can handle up to 64 GB, but a 64 bits host would be better.

ThomasLocke wrote:I'm very familiar with Slackware, so I will probably go with that as the host OS, unless of course there are some benefits from going with an OpenSolaris/VirtualBox combination?

We basically treat all hosts in a similar way, so there's no clear-cut advantage of going for Solaris or Linux. Each OS has its own strengths.

sandervl wrote:For RAM it's simple math. 20 x 512 = 10G, so get at least 16 GB. It all depends on how many resources an average VM needs; cpu and memory wise.

It seems that a VM's RAM is allocated as Locked (non-pageable) RAM in the host (Windows). Is this correct? (Starting multiple VMs causes problems when TaskManager/ProcessExplorer indicates physical memory close to 100%, even though virtual memory is ~60%.)

MarkCranness wrote:

sandervl wrote:For RAM it's simple math. 20 x 512 = 10G, so get at least 16 GB. It all depends on how many resources an average VM needs; cpu and memory wise.

It seems that a VM's RAM is allocated as Locked (non-pageable) RAM in the host (Windows). Is this correct? (Starting multiple VMs causes problems when TaskManager/ProcessExplorer indicates physical memory close to 100%, even though virtual memory is ~60%.)

Yes.