virtualbox.org

Hi,

I would like to know if there is any possibility to run 25 guest under one host. What is really needed to support that large number of guests?

My computer spec: Windows XP 32 bit, Intel Core 2 Quad Q6600 2.40 GHz, memory 2GB RAM

My guests' OS are also windows XP. I don't need intense graphic support for each guest though. The thing is, I need to run many typical light weight program (just 30 mb) but this program only can be used one per computer. I need to run 25 of them. I can't possibly buy 25 more desktop so I make 25 guests.

I try to run just 10 of them, but my computer get so slow. Right now I put 65MB base memory per guest so my computer should still can handle them, calculating that 65MB x 25 = 1625MB (1.6GB) So I decreased the graphic support for each guest. Set the desktop to none (not using any wallpaper), reducing color quality to 16 bit instead of 32 bit, and set the hardware acceleration ('troubleshoot' tab in 'default monitor and properties' option) to none.

Is there any way to run each guest's graphic to get lower than this or method to lower memory requirement to the lowest level?

Thanks all for your support

You really want to run a Windows XP guest with only 65MB of memory? I would expect the guests to run very slowly.

Yeah, I do run them in 65MB memory and they run well although not as fast as the host. I don't install anything, just running a 30 MB program. Set it to the minimum (65MB RAM, 2.21 GB virtual harddisk).

I'm just wondering if I run 25 guests will they make the host run very slow? As I say I the guests are all in minimum graphic support.
Oh, and one more question, is the memory of host being taken by guest's base memory?

Probably the host will be slow but running 25 guests with non standard memory allocation at 1.6 Gig of total memory provided and that many on the same hard drive should be a sight to see. If they all kick off in at the same time I bet you could drink coffee and even cook breakfast before they were all up and running.

rainyday wrote:I'm just wondering if I run 25 guests will they make the host run very slow? As I say I the guests are all in minimum graphic support.
Oh, and one more question, is the memory of host being taken by guest's base memory?

Yes, 25 guests will make your host run very slow. I would guess that 4 guests would make your host run very slow.

And yes, the guest's memory comes from the hosts memory.

I can confirm that with just one guest it is possible to slow down the host quite a lot. I'm running a Win7 guest with 960mb RAM (slightly below minimum spect for Win7) on an Althon 64 x2 laptop with 2GB RAM I am using a shade over half the host RAM meaning I sometime struggle to get it running at all, and then I find the XP host is on a go slow too. Wherever possible, leave at least 1GB ram untouched for the host. This means you can only really allocate around 900-950MB to the guests, which comes out at a mere 38MB per virtual machine including video ram. If you want to run 25 guests, get more memory (remembering that 32bit OS's cannot see anything above about 3.5GB so you're not that much better off) or get a new high spec PC with loads of memory and a 64bit operating system. If you manage that and can get 12GB installed (it would require a core i7 processor tomget that much in) you would be able to give each slice of memory to each virtual PC, and performance would be much better.

mark rumsey wrote:I can confirm that with just one guest it is possible to slow down the host quite a lot. I'm running a Win7 guest with 960mb RAM (slightly below minimum spect for Win7) on an Althon 64 x2 laptop with 2GB RAM I am using a shade over half the host RAM meaning I sometime struggle to get it running at all, and then I find the XP host is on a go slow too. Wherever possible, leave at least 1GB ram untouched for the host. This means you can only really allocate around 900-950MB to the guests, which comes out at a mere 38MB per virtual machine including video ram. If you want to run 25 guests, get more memory (remembering that 32bit OS's cannot see anything above about 3.5GB so you're not that much better off) or get a new high spec PC with loads of memory and a 64bit operating system. If you manage that and can get 12GB installed (it would require a core i7 processor to get that much in) you would be able to give each slice of memory to each virtual PC, and performance would be much better.

You should not need to use Core i7 if you need 12GB RAM. A current Intel P43/P45 motherboard can support up to 16GB RAM with Core 2 Duo / Core 2 Quad CPUs.

rainyday wrote:The thing is, I need to run many typical light weight program (just 30 mb) but this program only can be used one per computer. I need to run 25 of them. I can't possibly buy 25 more desktop so I make 25 guests.

I try to run just 10 of them, but my computer get so slow.

apart from RAM questions - what are the guests doing? are they just sitting around and wait for rare requests?

if you want to use them for long running computational tasks you have to restrict their number to the number of CPU-cores in your system (1xquad=4), and count one core for the host if your computation is running there too. Excess number of guests will steal CPU time from other guests and thus generate additional scheduling overhead

dmcgraw wrote:

rainyday wrote:I'm just wondering if I run 25 guests will they make the host run very slow? As I say I the guests are all in minimum graphic support.
Oh, and one more question, is the memory of host being taken by guest's base memory?

Yes, 25 guests will make your host run very slow. I would guess that 4 guests would make your host run very slow.

And yes, the guest's memory comes from the hosts memory.

I've had 4 running at the same time, with no unexpected performance impacts as long as I had enough RAM. Push the limits on available RAM though, and everything gets real slow.

Thanks all for all your reply. Now I know that with my current computer I can run just 10 windows XP guests after testing it. More than that and it becomes reeeaaallyy slow.

Now a bit off topic, is there any way to run a program which only can be run in windows XP, 2000, and 2003 in windows 98? Or maybe 98 Second Edition?
I want to run 25 guests but my computer only allowing to run 10 XP guest but I can run 25 or more guests if they are in windows 98

Add more ram to the Host.

I think that you will find running more than one Win98 guest will slow things down. It really was not built to be in a virtual environment. My processor hits 80% plus on the core that it is using with one Win98 guest when I run it.