20 Virtual machines on vmware

Lets say I wanted to setup a home lab using VMware (rackmount or any other server) to host approx 20 virtual machines, what kind of setup would I need?

at the moment I have an 8 gig dell power edge 1950 with 2 processors I think..... I want to install sccm 2012, sql , scom 2012 - whole mini corporate infrastructure!!!!!!!!!!!
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Seth SimmonsConnect With a Mentor Sr. Systems AdministratorCommented:

the present configuration is sufficient as per requirements mentioned in the VM host Hardware requirements.

it was sufficient nearly 10 years ago when that article was written


I would look at the system requirements for each application you want to run and base your capacity plan on that.  Clearly your dell server is insufficient to handle that.

Supported Configurations for Configuration Manager

System Requirements for System Center 2012 - Operations Manager

Hardware and Software Requirements for Installing SQL Server 2012
bbaoIT ConsultantCommented:
for setting up a lab of all 2012 series OS and application servers, the 8G RAM seems not sufficient for runnig most or all VMs at the same time.

you do need large memory and fast storage. try at least 64 GB RAM and 1TB SSD.
Sajid Shaik MSr. System AdminCommented:
the present configuration is sufficient as per requirements mentioned in the VM host Hardware requirements.


it's depends up on how many vm you will run at a time online...

for example about the memory u can easily calculate on the base machine or host machine u should have atleast 1 gb, and assigned memory to Vm's .. and assigned processors to vms...

for example u have 4 core processors x 2 = 8 cores

u assigned 7 vm's each core...and left 8th core for the host machine...  as well as ram


it's Ok

if u want to assign more than avail .. i.e u can shut down the host and created another host... vise versa... u can create but it'll be heavy to get performance ... and it may be crash...

so hardware sizing is very important...

all the best
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bbaoIT ConsultantCommented:
> u assigned 7 vm's each core...

are you able to assign one VM to use a specific core of your CPU in VMware? i am afraird you can't do that, you can SUMULATE (not assign) multiple cores for a VM, but you can't assign one or more specific cores to a VM.
rindiConnect With a Mentor Commented:
First of all check with the VMware "Hardware Compatibility List" whether your server is supported. It looks as if you need a PowerEdge 1950-III for VMware ESXi 5.5, while for older VMware versions (5.1) you can also use the normal PowerEdge 1950 (without the -III).

As already has been mentioned, you will need to add RAM. Generally you need as much RAM for your host as the separate hardware would need for running the physical servers you want to run simultaneously. So check the minimum requirements of all the OS's you want to run at the same time. The ESXi host itself hardly needs any RAM (+/- 32MB), not "at least 1GB" as has been mentioned above,

Get a USB stick to install ESXi to (or an SD card). many Servers include an internal USB port or SD card reader just for that.

You also won't need SSD disks, that's too expensive just for a test environment, Standard Server disks will do fine. But make sure you have enough capacity for all your VM's.
Gary CaseConnect With a Mentor RetiredCommented:
To really answer your question you need to be more specific.

For example, I have about 40 VM's ... just about every incarnation of Windows plus a few with multiple configurations; plus several Linux VM's; plus some old DOS systems.   HOWEVER, I rarely use most of these -- and never have more than 3-4 running at once.

If I wanted to run all of them at the same the the hardware requirements would be FAR different.

From your initial description it sounded like you want to run quite a few at once ... to essentially emulate a small corporate infrastructure.    That will require far more than 8GB of RAM ... and to get good performance you'll likely want a high-end dual processor system.

But without more specifics, it's simply guesswork to speculate on just what you need to run these all with reasonable performance.
bbaoConnect With a Mentor IT ConsultantCommented:
let's say the author does need to run 20 VMs simultaneously for whatever reasons.

as nowadays all MS 2012 series servers, including Windows 2012 and heaps of application servers such as SCCM 2012, SCOM 2012 and SQL 2012, need 2 GB as a practically minimum memory requirement. hence 40 GB memory MIGHT be required. the reason of saying 'might' is because latest VMware technologies now allow sharing memory across active VMs, therefore running 20 VMs does not actually need 2 x 20 = 40GB RAM to be allocated.

but in a real world, some VMs do need more RAM for their services to be accessed or shared by other servers, e.g. SQL services may be accessed by all S**M 2012 servers, so 2GB is obviously not sufficient.

IMHO, SSD is reuqired for such as a lab environment running 20 VMs simultaneously, because the disk storing the  VMs will be very busy in responding the activities of the VMs. althoughit is only a lab for testing or demonstration, disk will still be a major bottleneck due to physics limitations of traditional HD in term of track seeking ,space addressing, file writing and reading.therefore, running VMs on SSD can siginificantly improve performance in such a scenario.

i personally have such as an environment at home: VMware running on 64 GB RAM and SSD. it runs beautifully. :-)
On such a server he'll be using several disks in RAID arrays, so the disks shouldn't be that much of a bottleneck even for several VM's running simultaneously. Besides, SSD's for so many VM's would require pretty large SSD's, and those are still very expensive. In a testing environment where data redundancy isn't that important, you could even use RAID 0 to get optimal performance.
bbaoIT ConsultantCommented:
> using several disks in RAID arrays

i guess hardware RAID0/5 or even SAN could be more expensive than single SSD for a home user? :)
It's a Dell PowerEdge server with RAID controller, he probably already has some disks with it.
You need Enough memory to run the host operating system


memory required for EACH guest operating system running at the same time

This includes memory for applications that are running on host system
and on the guest systems.

If you were to run several Virtual Linux machines, or several Windows machines, look at the memory suggested for each virtual OS, plus the suggested memory for the hosting machine.

Every VM uses memory, the host uses it.

Assume minimum 4 GB for the host
plus 1 GB min for each guest (VM) x 20 = 20 GB

Total of 24 GB. If your guest VMs need 1.5 or 2 GB each, factor that in as well.

Hope this helps.

As I mentioned earlier, ESXi requires only very little RAM, something around 32MB, which is in no way close to 1GB or the 4GB you mention now. You can safely say that what the host uses is irrelevant compared to the VM's, and you don't have to take it into account.

Other HyperVisors may need more, like Hyper-V, but not ESXi.
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