Which motherboard for how many virtual servers?


I need to know how many virtual servers it’s possible to run on the same machine with virtualmin pro and which machine is the best for doing it.

I know that it will probably depend on these webserver needs but if it’s possible to have an approximation, it will be great.


ps: Dont try to insulte me if you dont know…


love<br><br>Post edited by: PatTzZ, at: 2009/03/31 20:35

How long is a piece of string?

The answer really depends a lot on what you’re doing.

We have some hosts that are running hundreds of domains on a single modest system. While we also have folks who are only running a few websites.

The most important consideration is almost always memory. If you want to fit a lot of servers on a single machine, you need a lot of memory. For hundreds of sites, I would recommend 4GB+. If you wanted to push it and try for thousands, you’d want even more. 8GB might do it, but 16GB would be better. This is assuming relatively lightweight sites without huge traffic, obviously. High traffic sites present several issues of their own, and have to be dealt with in non-generic ways.

Of course you need enough disk space for all of your sites and mail and such, but the definition of "enough" is variable.

And, you’ll need enough CPU horse power. But, modern CPUs are all really stupidly fast…so almost anything will do. If you’re processing a lot of mail, this might not be entirely true. ClamAV and SpamAssassin are quite demanding of memory and CPU, so you might need to plan for a mid-range CPU at least if you have hundreds of sites and lots of mail going on.

Beyond those basic guesstimates, we can’t provide anything concrete without specific details of your specific usage.

I agree RAM is very important and I would suggest 10k scsi drives as well. I wouldn’t run a production server with less than 4GB ram.
I run a dell server (PE 1650) and also a newer HP dualcore as a testserver.

Thanks for your help!

We need to host few hundreds of websites and some of them have a lot of traffic on and need to send a lot of newsletters.

Some friends told me that it’s impossible to use virtual servers for sending a lot of emails and having all going well.

They told me that we need one machine per host, so i need to be sure if it’s better for us to work like that or if it’s possible to work with less hardware with virtual servers.

In my mind, i know that some organisations are using virtualisation for a lot of things and i think that it’s possible but maybe that i’m wrong.

So, if it’s possible, i will going to talk with centos developpers to know what are the best compatible machines to work on.

If you know centos and compatible hardware a lot, please let me know what is the best to use within that stuff: (small ones for independant hosting or big ones for virtual servers).



Your comments and suggestions are appreciated.

Thanks and regards!

Scuze me to double post but i tried to edit and it was impossible.

I wanted to say that i know that is possible to hardwarly upgrade all of these servers but a had a lot of problems with centos and ics motherboard so i dont want to loose my time with drivers problems and bugs.


Well, I want to make sure there isn’t any confusion going on here – in the Virtualmin world, a “Virtual Server” refers to a domain on a shared server… it doesn’t imply any level of virtualization.

You can certainly run multiple Virtualmin Virtual Servers on a single server.

You can also run multiple virtualized servers on a single server.

And exactly how many of those you can run are going to depend on the resource requirements of each :slight_smile:

Also, for my users who deal with newsletters and such – sending mass amounts of email takes a lot of resources. I setup a dedicated system just for them, and have their software spread the load out over several hours.


Did you tried few hosts on the same server for that kind of activity?

If yes, what was the results?

Thanks to help!


Well, I’ll offer two examples – both Virtualmin Virtual Servers, as well as Virtualization.

Virtualmin wouldn’t offer licenses for 250 domains on a single server if it couldn’t work. I’ve seen systems running well over 100 Virtual Servers (ie, domains), and the server was doing fine.

On the other hand, I’ve seen a server having trouble keeping up with 5 domains when those 5 domains were extremely popular :slight_smile:

On the Virtualization front – with enough RAM and CPU, you can run a boatload of server instances on one piece of hardware. Linode, a VPS company who uses Xen for their servers, tells how many Xen instances run on each server here:


For the lower end VPS’s, they have 40 Xen instances on one server. The higher end VPS’s have as few as 5.

So again, it all comes down to your specific usage :slight_smile:

If you’re concerned as to whether it would work, you could always set up your server with one or two, and slowly add more domains to it as you learn how the system handles the load.

We need to host few hundreds of websites and some of them have a lot of traffic on and need to send a lot of newsletters.

few hundred? like 200 or 400?
lot of traffic? like 100.000 hits per site per day? or just 20.000?
lot of mail? like 10.000 emails a day? or 1.000.000

those are big differences.

I would suggest to get your self a 16GB, double quadcore powerhouse and 2 mailservers, double the fiber uplinks and be prepared to add another server.

centos is running great on my dell and hp server.