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Need help with Hyper-V

Howdy all,
Please pardon my ignorance here concerning Hyper-V. There are tons of differing opinions/instructions on the net, which does nothing but add to my confusion. I know this is lengthy, but hopefully, when solved, it will help other “newbies!”

I have a new high power server that I have plenty of time to play with before I put it into production. It is going to replace a SBS 2008 box that is currently a DC/File/Print Server on a 30+ workstation network. The new server: Dual 2.5 GHz. Processors, 128 GB ram, 6 hot swap drives (2 x 350 GB (RAID 1) and 4 x 1.2 TB (RAID 6)), 2 Dual Port NICs, redundant hot swap power supplies, etc.

My original setup on this machine was the OS (Server 2012 R2) was on RAID 1, performing AD/DC/DHCP/DNS functions and the RAID 6 drives were for data, roaming profiles, user files, mail PST’s, etc. Basically, a glorified desktop with plenty of punch and redundancy. KISS!

Initially, using the GUI, I had all the bells and whistles installed. All 3rd party software (Dell OpenManage, Symantec Backup Exec, WSUS, Antivirus, etc.) seemed to cooperating nicely with the OS. All OS updates and patches had been applied. Being on a 350 GB drive, there was plenty of room to spare. I have since experimented with removing the GUI and using PowerShell, but it’s a nice feature to be able to switch back and forth.

One of the primary programs I need however is SQL Server (2014). It will be hosting back ends of two large databases. Both get lots of read/write activity. Here is where my problems began. Turns out that Microsoft Best Practices recommend against installing SQL on a DC. This forced me to seek alternate installation options and hence, Hyper-V!

At this point, I knew nothing of Hyper-V and was suddenly thrust into its clutches! I posted an earlier question in this forum concerning this issue. It was recommended that I create two virtual machines. One, to act as AD/DC and the other to host SQL. This, at the time, seemed logical and I set out to create my 1st Hyper-V machine. Once done, I installed the same OS and began experimenting with the myriad of configuration options. How much disk space to allocate? Memory? Can it access the data drive? Where (host or guest) do the 3rd party software programs get installed? The questions began to mount, resulting in a sleepless night!

Here’s where I need a guiding hand and expert’s opinion! Since this will be a single server network, my thinking has now come full circle. I’m back to KISS! Is it feasible to have the host machine as my DC/AD as explained in my original glorified desktop setup plan? Then, create a Hyper-V guest, install the same core OS that will host SQL?  If so, do I need to consider partitioning the OS and/or DATA drives?

This seems to me, for a single server solution, a logical deployment plan. However, if you disagree, or have a better, more efficient solution, your comments, suggestions, instructions, links, etc. are greatly appreciated! Is there a step by step for my particular scenario (for dummies) anywhere? Currently, the server sits idle awaiting further research! The core OS is installed on RAID 1, single partition and the RAID 6 DATA drive is initialized and formatted on a single partition. The OS is a clean install, with no updates applied. Like I said, I have plenty of time to “play!”
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DonNetwork Administrator

Your host machine should do one thing only and that is run Hyper-V. You have plenty of RAM and space to add quite a few Virtuals (Hyper-v guests). Have you gone over ??  http://blogs.technet.com/b/askpfeplat/archive/2013/03/10/windows-server-2012-hyper-v-best-practices-in-easy-checklist-form.aspx

⎕ Do not install any other Roles on a host besides the Hyper-V role and the Remote Desktop Services roles (if VDI will be used on the host).

    When the Hyper-V role is installed, the host OS becomes the "Parent Partition" (a quasi-virtual machine), and the Hypervisor partition is placed between the parent partition and the hardware. As a result, it is not recommended to install additional (non-Hyper-V and/or VDI related) roles.


Hi dstewartjr and thank you for prompt response to my questions. Yes, I have seen and printed above link. However, my questions still remain: 1) I setup two Hyper-V roles on host machine. All participants running Server 2012. One guest will be AD/DC, the other is for SQL. Where does all the other stuff go? For example, I love the remote ability to inspect system health in a glance. Dell's Open Manager works perfect for me. Where does it and other functions (i.e. WSUS) go? On their own VM's, or on the host partition? Do I need to do any partitioning of DATA drive to make the VM's be able to see/use it? How about memory allocation and virtual processor count for the various VM's?

Yesterday, after installing/experimenting first VM, I noted that the only way it could see/use the DATA drive, was to first take the drive offline. Once I linked it to the VM, it was as if no other VM was going to be able to access it. Therefore, my concern about first partitioning it for future VM's. If my first VM is a DC/AD/DHCP, etc., I would also want it to handle user profiles and files. Therefore, it would need to store the data on my DATA drive. If second VM is hosting SQL Server, I would possibly need some additional data space down the road...You see why I was unable to sleep last night?
Philip ElderTechnical Architect - HA/Compute/Storage

I have a great Hyper-V Hardware and Software Best Practices article here.

Please have a read through that to some guidance on how to set up the server.
Distinguished Expert 2018
In answering your follow-up questions, it bears repeating; The host should *only* be a host. (yes, this actually answers many of your questions!)

Where do you install the other stuff?  WSUS? In a VM!  Antivirus?  In a VM!   Leave the host pure.

As far as the rest, don't overthink it. How much memory would you normally allocate to a DC if you were spec'ing a physical server?  Microsoft has guidance on this based on user count and other factors.  The fact that it is a VM doesn't change this.  Run their calculations, use that many vCPUs and that much memory and you have a good baseline for that VM.

Regarding data, don't take the physical RAID logical drive (god that sentence hurts)  offline.   Create virtual disks on the physical drive (VHD or VHDX files.)  You then add a VHDX file you created to a VM and...presto...that virtual drive is seen by the VM. You can format it, work with it, whatever. So you can create three VHDXs if you wanted, put each on a different VM, and then you have three VMs accessing space on the physical data partition (not the *same* space obviously.)

You should buy a book on Hyper-V and read up. You'd have hit these same issues even with your "simple" setup trying to run just one guest while keeping the host a DC *and* a hyper-v server. The fundamentals of Hyper-V really don't change whether it is one VM or twenty. SO adding the second VM isn't complicating things as much as you are making it out to be.  It is just a learning curve and you are jumping into the deep end without having learned to dog-paddle yet.  No big deal. We all learn somehow. Just not a great idea to do so on production environments.


Thanks Cliff...It is all beginning to make sense now. Coming from a programming (C, C++, Assembly, Pascal, VB, VBA) background, I was thrust into the position of network Admin quite accidentally. Now that I'm there, I intend to create the best, most reliable, efficient system within my power. I'm really glad the new machine is not going online until beginning May! Gives me plenty of time to read the Hyper-V and Server 2012 books that are otw. Also, being a PADI Scuba Instructor, for me it IS sink or swim!

In summary, I understand:
1) The host is only a bare bones host and should remain that way. Only core OS and Hyper-V.
2) Once AD/DC guest is created, I can link it to a virtual drive earlier created for storage of user stuff...
     A) What is recommended utility to create virtual disks?
     B) Do you rx that WSUS, Antivirus, other utilities go on separate VM, or existing?
     C) Core or GUI on these VMs? I know it can be added removed fairly easily with PS.
3) Allocate memory, disk space, vProcessors as needed per MS recommends based on work load.
     A) If I have a total of 128 GB physical ram, does for example, utilizing 40 GB for the AD/DC subtract from that        total?
     B) Does the same apply for the RAID 6 array with 2 TB space when allocating virtual hard drives?
4) Assuming I install Server 2012 R2 on all VMs. Do these need periodic updates like the host OS?
     A) Can the VMs get theses updates from WSUS if it is installed for example, on the DC VM?

I look forward to jumping back in the pool!
Distinguished Expert 2018

1) Correct.

2A) Whatever you are using to create the VMs.  If you are using SCVMM, use it to create the virtual disks as well. If you are using Hyper-V manager, use that. The functionality is built into most tools that are used to manage Hyper-V.

2B) That depends on the environment. With the cost of virtualization going down, I generally prefer DCs also be "just" DCs. So WSUS would usually go on a VM used for hosting applications. Whether that is your planned SQL server or whether that'd be a 3rd VM would depend on the needs of that SQL server and potential conflicts.

2C) Again, depends on the workload. I run my DCs core. Some applications require the GUI. You can mix and match. They don't all have to be core or all GUI.  

3A) Yes, allocating memory to a VM reserves it and is no longer available to other VMs or the host.   There is a nuanced argument here regarding dynamic memory, but I'm sure you'll read about that and it doesn't technically change my argument. Two VMs cannot access the same memory at the same time. Dynamic memory (which I don't recommend using in your case) just allows the host to rob memory from a VM that isn't using it and can give it to another VM that is requesting more. But even then, the total memory used by VMs and host cannot exceed the total physical memory.

3B) Yes.

4) Yes.
4A) Yes


And, that's a rap dude! Thanks a bunch for taking time to answer my questions...Anything you need to know about scuba diving, lmk!
DonNetwork Administrator

Glad I helped ???


Yes, sorry dstewartjr....I was thinking of splitting the points between you and Cliff, but Cliff gave more concise answers to my questions. Again, thank you for taking the time to respond to my q's! Cheers...