How many Virtual Machines should run on a 4GB of RAM?

[drummelhart]

I have finally learned how to clone a Virtual Machine, I believe using VMWare Server 2.0, and now I am trying to figure out how many Virtual Machines could run simultaneously with the Host OS? I have a 2.0 Ghz Proc hoping to get a 2nd Proc; however, unless I run a x64 bit OS, I can only run at this time 4 GB of RAM.

What are you running via CPU and RAM on the Host SVR and how many VM's are running at a time?

 

[TheLad]

How much memory do you intend to allocate to each VM?

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[ArizonaGeek]

With VMWare server and 4 gigs of ram you probably wont get more than 2 or 3 VMs going on it. If you were using ESXi you could probably get 4 or 5 easy even with one processor. Kinda depends on what you allocate to your VMs.

I am using the enterprise version of ESX on three physical servers. Dell 2950s. No internal drives, we're booting from our SAN, 32 gigs of ram each quad NIC plus 2 on board, dual quad core processors on an EMC 8tb fiber channel SAN. I have about 35 servers going and are less than 30% utilization across all three servers.

The answer is always "PEBKAC!

 

[drummelhart]

Memory wise depends on what I am trying to run. Other than a Secondary DC, I think most of the Servers will be WFE and need approximately 1 gig of ram. If I see that the RAM is just sitting there, I may cut them all down just a hair. What I would not want to do is exceed the boundries, and crash the host OS.

 

[biglebowski]

At home I'm running ESX 3.5 on an ML350 G3 with dual 3GHZ xeons, 4GB RAM and 6x 146GB hard disks and I can run 7 VMs

Call manager - 2048MB
2k3 server DC - 2048MB
5x 2k3 server - 512MB

They will all run ok but web access to the call manager can be slow when being pressed hard.


When I was born I was so suprised I didn't talk for 18 months

 

[SimonDavies]

But memory management under ESX is handled differently, it will offload some of the memory management between other guests that aren't utilising all of theirs. If you suddenly put all of those boxes under load you would find you have issues getting them all to run right.

As far as using a Windows OS with the VM server product goes, you have to take into consideration on the Windows OS requirements as well, you're far better off using a dedicated ESXi environment with a much smaller footprint over using a Windows based OS and then the VM server on top of that.

Ideally speaking you would be looking at no more 3 or 4 machines active at any one time, also worth mentioning is that the limitation on 32bit OS's is actually closer to 3gb rather than 4 (and that's combined memory so that would also include video memory as well), unless of course you're using an Advanced version of Windows Server to host on.



Simon

The real world is not about exam scores, it's about ability.