Network bandwidth issue

marka211

Weaksauce
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Oct 1, 2000
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I work for a Microsoft Certified Refurbish-er of PC’s. Recently, we started using a WDS/MDT system to install images to the computers. Previously we were cloning HDD from images. My boss set it up so we have the ability to image 24 computers at once. But the issue we have run into is:

If any 2 computers are copying images from the server, it is making the rest of them wait till those 2 are done. All of this is running over 1 gigabit network port and when I bring up task manager that port is doing somewhere around 105 mbs.

Quick network topology: Dell power edge server running 2 VM’s though hyper-visor, then out one port to a switch, then from that switch to 2 other switches, each switch is running 8 machines.

This power-edge server has 4 ports all are gigabit, one is used for remote access and one is used for the WDS/MDT part. Is there a way to use the other 2 ports for the WDS/MDT or is there a better way to setup this network so we can run all 24 machines at one,

Warning, I did not set this up, or configured the server, I was asked if I could look into this issue and see if I could find a solution, mostly because I have the most network knowledge where I work, though that is very limited knowledge.

Hopefully this post is understandable to people with a lot more expertise than I.

Thanks
 
If you are only seeing 100mbps utilization on the server task manager, then this sounds like a disk problem rather than a network issue.

To answer your question, you could setup a NIC team on the 2 remaining NICs plus the connect these NICs to an LACP group on the switch. This will give you higher theoretical maximum throughput, but you won't get any higher than 1Gbps on any single stream.

https://docs.microsoft.com/en-us/windows-server/networking/technologies/nic-teaming/nic-teaming

Another thing you can look into doing is configuring your MDT environment for multicast, rather than relying on unicast.
 
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My boss set it up so we have the ability to image 24 computers at once.

Thanks

No, it sounds like they failed at that task... A quick search turns up that WDS should support multicast. IE, 1 transfer of the data can be received by a large number of computers all at the same time. So it sounds like what you are doing is 2 unicast requests, and there is probably a limit to the number images processed at a time. If you get multicast working correctly, you should be able to send the same image to all 24 pcs at 1 time, and it will only use the same amount of bandwidth required to image 1 computer.

https://technet.microsoft.com/en-us/library/dd637994(v=ws.10).aspx
 
First, I think you are confusing terms. b = bit, B = Byte (8 bits). 1000Mb/s = ~112MB/s (105MB/s sounds about right with the overhead of each packet). I see nothing wrong with the speed.

Like others have said, you can team 3 adapters together (even if the switch is LADCP aware), which will at least allow you to send 3 separate streams at 105MB/s, which should at least triple the number of servers you can deploy to. Multi-cast would work if you are sending to 24 at the exact same time.
 
Thanks for the replies!

I'm not sure why multicast is not working. Is there a setting in windows or in the hypervisor that I need to make sure that is on for the multicast to work or is that the default behavior? My boss wants to try teaming to get the other 2 NIC's working just in case we need the bandwidth or he wants to add more systems to image.

EDIT: looking at the link for creating multicast transmission, seems my question has been answered, and I believe this is on Windows Server 2016 so hopefully the instructions on that link still work, i will see if it is even setup like that, if not then I assume that it is setup for unicast and is the root of the issue.
 
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