Hyper V run very slow on Windows 2012


I installed Windows server standard 2012 with Hyper V role on a box running an Asus Sabertooth Tz77 with an intel I7 3770 running at 3.5 ghz and a realtek gigabit network card and 16 gig of Ram.
Windows on the host load fast and work fine until I start to create the virtual machines and fire it up. First VM is a domain controller running windows 2012 standard and I assign 4 gig of ram. Second one is running SQL 2005 and it has 4 gig of ram assign. And the 3th one has IIS with an application that run under Asp 2.0 sp1.
When all those VM are on everything goes sloooooow on all the VM.
One at the time is Ok but not all 3.
I run the exact same VM on a server before with less ram and processor power than this one. The only diference was that it was under win 2008 hyper V not 2012.
What can be different on 2012 that slow it down so much?
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infedonetworkConnect With a Mentor Author Commented:
Increasing the ram and assigning a different nic solved the problem.
infedonetworkAuthor Commented:
I forgot to mention that the HD activity on the host is very high.
Looks like the VHD and VHDX for those 3 virtual machines keep the high activity running.
Lee W, MVPTechnology and Business Process AdvisorCommented:
You need to clarify:
1. What is your disk subsystem (DETAILS)
2. Are you using Dynamic RAM?  If so, with which server(s)?
3. How much RAM are you allocating to third VM (the ASP 2.0 SP1) system.
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infedonetworkAuthor Commented:
All vm use 4 gig each with dynamic ram enable.
The host has a sata 3 drive and 2 use vhd and one vhdx drive.
If I run one vm the speed is Ok but when I run all then is very slow.
the hard drive light on the server is almost on all the time.
Lee W, MVPTechnology and Business Process AdvisorCommented:
So you're running a SINGLE SATA3 drive?  No RAID?  7200 RPM?  For 3 VMs and the host operating systems?  Are the VHDs fixed or dynamically expanding?  Again, DETAILS.

What is the purpose of this server and it's VMs?  Testing?  Development?  Production?  

What is the load like on the VMs?  Are they being hit with 1000s of requests from clients per second or is it just you?  What does Resource Manager say each VM is using, disk wise?
I'd like us to return to the core question, which is a comparison of performances of Hyper-V on 2008 and 2012 server.

You said, on 2008 it appeared faster. For this comparison to make any sense at all, you would need the same virtual machines running and the same hardware underneath. This is not given here but you say, CPU-wise and RAM-wise, the 2012er should be superior, but it obviously isn't.

Please add details: was it a comparable disk subsystem on 2008 (single drive as well? Same drive performance?)?
Were the machines the same or at least of comparable type?
Were the virtual hard disks pre-allocated? Are they prealloc. now? (asked before, I know ;)

Anyway, leew's questions will have to be answered and the outcome will be most likely that your disk subsystem needs to be pimped, because even if you concluded the drive subsystem should be sufficient (as it is as strong as before, configured like on 2008), it most obviously ain't.
infedonetworkAuthor Commented:
Old server was an dell power edge 2900 and differences are:
old server:
xeon CPU quad
ram 4 gig each
hard drive raid one scsi

new server.
i7 3.5
ram 4 gig each
hard drive single sata 3 drive No raid

I convert acronis image of those servers in to vhd and after I installed hyper v on the new 2012 I create the vm and attached the vhd that was created from acronis.
As of know this remain on the lab until I test the upgrade from 2003 to 2012 on one of the vm.
If complete successful then I will ad a raid 1 before it goes on production.
I know the motherboard is not the ideal for a server but has some good horsepower and I want to test it before I spend more money on a new server.
This is not critical servers and they get image backup dailly.

I want to try something new today.
I will create a new vm with a fresh vhdx not an attached one.
then I will restore the acronis image to this new. Vhdx.
The reason is that I see on the 2003 one that the partitions has different drive than the original server and I can see those partitions under disk management.
It's a single one.
infedonetworkAuthor Commented:
And I decide to try on raid 10 with 4 wd 1tb 64 Mb buffer.
There is one I think with 152 Mb buffer but not sure how will work with 3 at 152 and one at 64
Lee W, MVPTechnology and Business Process AdvisorCommented:
Bottom line is this:

You are RADICALLY altering your config and it's still not clear what's going on because you keep leaving out details.

Hard drives are one of the MOST IMPORTANT factors in performance for virtualization and right now you're using cr@p for drives.  Before you used SCSI.  Though was it SCSI or SAS because I'm fairly certain the 2900 uses SAS, but I'm not positive.  And then how fast were the drives?  If this is AT ALL important, you should be sticking to a name brand server not moving to a custom built box using off the shelf hardware that would NEVER be recommended for servers.

Even if your purpose is basic and non-production, the fact that you're using a SINGLE desktop class hard drive for your system and you see constant disk activity should be enough to say "hey, the disk subsystem isn't what it should be".
infedonetworkAuthor Commented:
I agree and I allways use DEll Servers.
But what I'm trying to do is plan in a lab an upgrade of one of the 2003 server to 2008 and is not easy because of the application it run. Before I even think about upgrading the server I need to get those 3 VM running but at the moment is very slow.
Once I get them running I will have to decide if I get a new Dell server and use this one as a replica server for the VM or just keep this one as the main server for those 3 VM.
Is not as bad as it sound. It has a fast I7 processor (not sure how well it handles the Hyper V)
and If I create a Sata raid 10 with the controler that is built in I should (I think be OK)
Increasing ram at 32 gb should also help.
Just wondering if I decide to keep this as a server what type of Sata HD would you recomend.
I agree that the PC type are not very good and more you have more vibration it occur and more chances to fail.
infedonetworkAuthor Commented:
That's what solved it
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