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You can install as many as you have a license for. &nbsp;The TWO limit is for a single license of Windows 2012 STANDARD. &nbsp;And that is one licence PER 2 Physical CPUS in EACH Physical Server.<br />
<br />
If you want to run 4 VM's then if your host has 1 or 2 CPUs you need two windows 2012 Standard licenses. &nbsp;once you go to large numbers of VM's you will need to look at Data Centre Licenses.
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You might also want to check out resources on Virtualizing Exchange. &nbsp;<a href="http://blogs.technet.com/b/keithmayer/archive/2012/08/28/best-practices-for-virtualizing-microsoft-exchange-2010-msexchange-itpro-hyperv-vmware.aspx" rel="ugc">http://blogs.technet.com/b/keithmayer/archive/2012/08/28/best-practices-for-virtualizing-microsoft-exchange-2010-msexchange-itpro-hyperv-vmware.aspx</a><br />
<br />
I disagree with Rob G. - I used to work with an organization that has 3 exchange servers for 1000+ people, all running in VMs.
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Poorly configured systems are not a reason to avoid virtualisation. &nbsp;We have 4 exchange servers, 2 DB and 2 WFE, all virtualized and all running perfectly. &nbsp;These handle in excess of 4,000 mailboxes and uptime is as long as it wants between patching. <br />
Running 100 mailboxes on an exchange server should just about warm it up, Disk IO on a server with 100 mailboxes should not be a problem unless your mailboxes are all used for a few 1,000 emails a day per user.
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Lee, <br />
What was the VM? <br />
VM or virtual machine doesn't really help tell what the specs were.. <br />
I too worked for a company that ran VM's on Cray servers, which didn't have the same issue with a Microsoft exchange cluster a few years ago.. but those servers start at 130K... A little different then a typical dell.... <br />
<br />
<br />
<a href="http://www.cray.com/" rel="ugc">http://www.cray.com/</a><br />
<a href="http://www.cray.com/sites/default/files/resources/CrayCS400-ACBrochure.pdf" rel="ugc">http://www.cray.com/sites/default/files/resources/CrayCS400-ACBrochure.pdf</a><br />
<br />
Which at 40 Petaflops i am sure it wouldn't have the latency issues..
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I'll have to get back to you on the config and check with them. &nbsp;I'm fairly certain they've upgraded since. &nbsp;But I'm also fairly certain it wasn't a cray. &nbsp;Honestly I would question disk and RAM config if you were having problems with Exchange for 75 users.
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Neil, <br />
They get around 800 emails &quot;Per user&quot; daily, plus due to compliance they require journaling to be enabled. <br />
In addition to that there are email attachments on 90% of the emails... And for compliance i need to store all the PST files on the Exchange server, they are quota'd on the mailbox, but attached in 3GB increments every 3 months.. Roughly 1-2GB per month per user.. It's not easy.. Especially with one exchange server. <br />
<br />
the other Vm's on the system are.. <br />
Print server<br />
and two database servers, but they are low consumption servers.. DB size is about 100mb on each, and doesn't grow much..
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PST files???<br />
Why do you have PST files with an exchange server?<br />
Why do you have exchange databases on a RAID 6 configuration?<br />
<br />
Like I said, a poor config is not an excuse to blame virtualization.<br />
<br />
If your servers cost you 17K each then you should have a decent storage array that has correctly configured raid arrays for the systems in use. &nbsp;Exchange databases should be on Raid 10 for performance, system and logs can be raid 5/6 if cost is the issue.
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Hyper-v is as good a choice as any and in your case the cost is considerably less for Hyper-V.<br />
<br />
I'm sure what you are meaning with instances?<br />
<br />
You will have a host server set up with 3 VM's running on it. &nbsp;Where do instances come into it?<br />
<br />
Sorry if i misunderstand.
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I read somewhere that there was a two instance limit, but I think based on the conversation it is per Standard 2012 R2 license. The verbiage was tripping me up in the Microsoft licensing information.<br />
<br />
One last question since we've rattled some cages on best practices and configurations. Everything I've read points to RAID 10 as the preferred method for the arrays. What is the preferred method to partition the drives for the VMs. I read somewhere that Hyper-V installation and the VM database should be on separate partitions. What suggestions do you guys have for partitioning the array for maximum performance and security.<br />
<br />
Thanks
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Both VMware vSphere and Microsoft Hyper-V &nbsp;perform the same, and are very good enterprise Hypervisors.<br />
<br />
Licenses aside, you can create as many virtual machines (instances) as resources dictate, e.g. CPU and Memory, memory normally being the bottleneck.<br />
<br />
e.g. you will run out of memory, before CPU and storage.<br />
<br />
Depending upon the utilisation of your virtual servers, we usually scale 5-6 VMs per physical core.<br />
<br />
So we've had 40 virtual machines running on a <br />
<br />
two 8 core Xeon processors and 64GB or RAM .
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@ditobot, have a read of <a href="http://www.aidanfinn.com/?p=13090" rel="ugc">this article</a> for a very good explanation of how 2012 R2 licensing works with 2012 R2 and Hyper-V VMs in various scenarios. This helped me out greatly when 2012 R2 first came out and we wanted to spin up some 2012 R2 VMs for testing.<br />
<br />
As for RAID arrays, I usually configure a RAID1 array for the Hyper-V host installation and then a RAID10 array for the VMs, along with a single non-RAID disk for non-essential stuff like dedicated VHDs for pagefiles, VSS data, etc.
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<div class="content wysiwyg-content">
I am considering using a beefed up IBM server with two 8 core Xeon processors and 64GB or RAM to create a private cloud in our office. I am new to virtualization and I'm trying to wrap my brain around best practices and methodology behind creating said private cloud.<br />
<br />
Originally I was thinking of installing three virtual servers on this machine. A DC, Exchange 2013 and an Exchange 2013 front end server. I already have a standalone primary DC but I'd like to put a backup DC on this machine.<br />
<br />
I believe that there is a two instance limitation on Hyper-V but I'm not sure how the virtual servers are rolled out to those instances and what the limitations are. I've setup virtual Linux servers in Amazon's AWS environment and it's always been a machine per instance. <br />
<br />
Am I barking up the wrong to to accomplish what I am trying to accomplish? Should I be looking at VMware instead or is this possible in Hyper-V?<br />
<br />
Sorry for the potential vagueness of my question but I am having a hard time finding a starting point.<br />
<br />
Thanks in advance.
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I am considering using a beefed up IBM server with two 8 core Xeon processors and 64GB or RAM to create a private cloud in our office. I am new to virtualization and I'm trying to wrap my brain around best practices and methodology behind creating said private cloud.

Originally I was thinking of installing three virtual servers on this machine. A DC, Exchange 2013 and an Exchange 2013 front end server. I already have a standalone primary DC but I'd like to put a backup DC on this machine.

I believe that there is a two instance limitation on Hyper-V but I'm not sure how the virtual servers are rolled out to those instances and what the limitations are. I've setup virtual Linux servers in Amazon's AWS environment and it's always been a machine per instance. 

Am I barking up the wrong to to accomplish what I am trying to accomplish? Should I be looking at VMware instead or is this possible in Hyper-V?

Sorry for the potential vagueness of my question but I am having a hard time finding a starting point.

Thanks in advance.

How many Server 2012 R2 virtual servers can be installed in Hyper-V?

Virtualization is the act of creating a virtual (rather than actual) version of something, including (but not limited to) a virtual computer hardware platform, operating system (OS), storage device, or computer network resources. Virtualization is usually the creation of a system that executes separate from the underlying hardware resources, or the creation of an entire desktop for systems located elsewhere, similar to thin clients.

Virtualization

Microsoft Virtual Server was a virtualization solution that facilitated the creation of virtual machines on the Windows XP, Windows Vista and Windows Server 2003 operating systems. Virtual machines are created and managed through a web-based interface that relies on Internet Information Services (IIS) or through a Windows client application tool called VMRCplus. Features included Linux guest operating system support, Virtual Disk Precompactor, symmetric multiprocessing (SMP), x64 host operating system support, the ability to mount virtual hard drives on the host machine and additional operating systems support, including Windows Vista, and a volume shadow copy writer.