Performance
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domingo, 15 de enero de 2012 12:49
I have just set up a Windows Server 2008 R2 which acts as an Hyper-V host. The physical boxis not a monster machine, but it should be enough fort what it's meant to be doing.
Anyway, the machine has an Intel internal raid controller which is configured with two raid 10 volumes (write cashe enabled). When I test the speed copying files from guest to host I reach apx 60-70 MB/s. When I copy the same file within an Hyper-V guest the maximum speed is just 10 MB/s. How come?
Todas las respuestas
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domingo, 15 de enero de 2012 14:50Moderador
Hi,
Please check the following posts to see whether you can resolve the issue.
Slow SMB copy from VM to Host Hyper-V R2
Hyper-V File Copy Speeds Slow, from Host initiated copies
http://social.technet.microsoft.com/Forums/en-US/winserverhyperv/thread/ff9cfb50-649d-4e87-b87e-bddfb93e9883
Best Regards,
Vincent Hu
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domingo, 15 de enero de 2012 16:57
Oops,
Now I see that I made a false description of the error. The acceptable speed is experienced when copying files WITHIN the host environment, not between guest and host. All trafic within the guest OS (SBS 2011 Essentials) runs slowly though, both over network and internally between two mounted VHDs.
Since it's not just network traffic that is slow I don't think that the problem is related the NICs in this case.
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martes, 17 de enero de 2012 10:35
Does anyone have an idea what's wrong here?
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jueves, 19 de enero de 2012 14:27Moderador
Hi,
According to your description, it seems that the copy between Hyper-V hosts is ok, and the copy between the guest virtual machines (SBS 2011 Essentials) is slow. If so, please help me to collect the following information:
1. Is it slow when you copy between Hyper-V host machine and guest virtual machine?
2. When the copy between the guest virtual machines (SBS 2011 Essentials) is slow, do you connect these virtual machines to the same External VirtuL network, Internal Virtual Network or Private Virtual Network?
3. Do you get the same slow symptom between other virtual machines?
Vincent Hu
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jueves, 19 de enero de 2012 15:41
Hi,
According to your description, it seems that the copy between Hyper-V hosts is ok, and the copy between the guest virtual machines (SBS 2011 Essentials) is slow. If so, please help me to collect the following information:
1. Is it slow when you copy between Hyper-V host machine and guest virtual machine?
2. When the copy between the guest virtual machines (SBS 2011 Essentials) is slow, do you connect these virtual machines to the same External VirtuL network, Internal Virtual Network or Private Virtual Network?
3. Do you get the same slow symptom between other virtual machines?
Vincent Hu
It is slow when copying between guest and host. In fact all trafic is slow whenever the virtual environment is involved. I use only an External Virtual Network, but I don't think that the NIC part is related here since it's slow even between two internally mounted VHDs.
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viernes, 20 de enero de 2012 4:03
Hello,
Is the system fully patched? If not, check this out: http://support.microsoft.com/kb/2517329
You might want to check if you are actually achieving the same performance on disk. If you are copying in your host you will certainly have faster copies because it has much greater RAM. However, in the VM, you might find that the copy performs very fast, then slows down part way through the copy.
Nathan Lasnoski
http://blog.concurrency.com/author/nlasnoski/- Propuesto como respuesta Nathan LasnoskiMVP viernes, 11 de mayo de 2012 3:59
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viernes, 20 de enero de 2012 8:18
Hello,
Is the system fully patched? If not, check this out: http://support.microsoft.com/kb/2517329
You might want to check if you are actually achieving the same performance on disk. If you are copying in your host you will certainly have faster copies because it has much greater RAM. However, in the VM, you might find that the copy performs very fast, then slows down part way through the copy.
Nathan Lasnoski
http://blog.concurrency.com/author/nlasnoski/Yes, all available patches are installed on this server (and on guests).
You may have a point about the RAM, but when checking this in Task Manager the VM utilizes only about 20% of the memory?!?
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jueves, 26 de enero de 2012 15:48
Could it be that it's siply Hyper-V that has limited performace abilities?
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martes, 03 de abril de 2012 5:13
Hello,
I'd say certainly not. Is it slow when copying from VHD to VHD inside a virtual machine? How does it compare from VM to VM? What if you put it on different storage?
Nathan Lasnoski
http://blog.concurrency.com/author/nlasnoski/
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martes, 03 de abril de 2012 6:44It has been a while since I made these tests, but as explained above all trafic within the virtual environment (VHD to VHD, VHD to physical, physical to VHD, VM to VM) runs a lot slower than it does in the host environment.
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viernes, 11 de mayo de 2012 3:59
Just as a follow-up, you should validate the hotfix here is installed. I don't believe it downloads from Windows Update.
http://support.microsoft.com/kb/2517329
Nathan Lasnoski
http://blog.concurrency.com/author/nlasnoski/
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