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KVM behaviour
06-07-2018, 05:05 PM
Post: #1
KVM behaviour
We need to checkout some behaviour of KVM before we use KVM into production

Network
N1) On xen, if we run 'systemctl restart network', all VM's network connection would be destroy and cannot be connected back. We need to see if kvm got this problem and look for a method to fix the problem if the problem exist.
N2) We need to know the network performance between VMs as well as between VM and PH.

Disk
D1) We need to test the IO perf of disk on kvm
D2) We need to know how kvm determines /sys/block/sdb/queue/rotational is 0 or 1. This would affect a bug in YFS

Cpu Overcommit ( least priority )
C1) We need to know what would happen when CPU overcommit on KVM.
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06-07-2018, 05:08 PM
Post: #2
RE: KVM behaviour
@changxy,

please follow http://tab.d-thinker.org/showthread.php?tid=11430 to install kvm on tetra and test for the behaviours in headpost.
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06-11-2018, 02:05 PM
Post: #3
RE: KVM behaviour
(06-07-2018 05:08 PM)rayluk Wrote:  @changxy,

please follow http://tab.d-thinker.org/showthread.php?tid=11430 to install kvm on tetra and test for the behaviours in headpost.

Since I am using SSH to connect with tetra, I can't use virt-manager, there is no display for me. Do you have any advice for me?
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06-11-2018, 02:24 PM
Post: #4
RE: KVM behaviour
(06-11-2018 02:05 PM)changxy Wrote:  
(06-07-2018 05:08 PM)rayluk Wrote:  @changxy,

please follow http://tab.d-thinker.org/showthread.php?tid=11430 to install kvm on tetra and test for the behaviours in headpost.

Since I am using SSH to connect with tetra, I can't use virt-manager, there is no display for me. Do you have any advice for me?

I have suggested you to use qemu ( http://tab.d-thinker.org/showthread.php?...http://tab.d-thinker.org/showthread.php?tid=11430&pid=7509 ) to build VMs. Please let me know what do you want to use virt-manager for.
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06-11-2018, 02:41 PM
Post: #5
RE: KVM behaviour
(06-11-2018 02:24 PM)rayluk Wrote:  
(06-11-2018 02:05 PM)changxy Wrote:  
(06-07-2018 05:08 PM)rayluk Wrote:  @changxy,

please follow http://tab.d-thinker.org/showthread.php?tid=11430 to install kvm on tetra and test for the behaviours in headpost.

Since I am using SSH to connect with tetra, I can't use virt-manager, there is no display for me. Do you have any advice for me?

I have suggested you to use qemu ( http://tab.d-thinker.org/showthread.php?...http://tab.d-thinker.org/showthread.php?tid=11430&pid=7509 ) to build VMs. Please let me know what do you want to use virt-manager for.

I just want to try few KVM comments and make sure it works.
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06-11-2018, 02:56 PM
Post: #6
RE: KVM behaviour
(06-11-2018 02:41 PM)changxy Wrote:  
(06-11-2018 02:24 PM)rayluk Wrote:  
(06-11-2018 02:05 PM)changxy Wrote:  
(06-07-2018 05:08 PM)rayluk Wrote:  @changxy,

please follow http://tab.d-thinker.org/showthread.php?tid=11430 to install kvm on tetra and test for the behaviours in headpost.

Since I am using SSH to connect with tetra, I can't use virt-manager, there is no display for me. Do you have any advice for me?

I have suggested you to use qemu ( http://tab.d-thinker.org/showthread.php?...http://tab.d-thinker.org/showthread.php?tid=11430&pid=7509 ) to build VMs. Please let me know what do you want to use virt-manager for.

I just want to try few KVM comments and make sure it works.

I think you mean KVM commands.

If you want some "vir" command to verify that the VM is working, you can use virsh list.

But, please note that for the VM created by the qemu commands, they are NOT managed by the virsh commands.
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06-20-2018, 06:24 PM
Post: #7
RE: KVM behaviour
Just report.
1. Finished install kvm and virtual machine on my own computer 4 days ago. When I use the Centos-7.ios from tbg15, I can't install the virtual machine, it said can't get the software disk. I copied the Centos-7.ios from Ningbo Office. And it was okay to do.
2. I can't get the visual interface from tb15-6, the connection by using VNC to tb15-6 is successful, but since gnome is not installed I can't see anything.
3. Every time I virsh start virtual machine, I need to brctl addif br0. And when I configure the br0, the internet will be off or I still got the ERROR said "Cannot get interface MTU on 'br0': No such device". I am fixing that now.
4. When I use the virt-viewer to use the virtual machine, the mouse is easily get stuck. Fixing that too.
5. I have viewed the document which KVM official website linked: http://linux.dell.com/files/whitepapers/...http://linux.dell.com/files/whitepapers/KVM_Virtualization_in_RHEL_7_Made And try to learn more.
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06-21-2018, 03:33 PM
Post: #8
RE: KVM behaviour
(06-20-2018 06:24 PM)changxy Wrote:  Just report.
1. Finished install kvm and virtual machine on my own computer 4 days ago. When I use the Centos-7.ios from tbg15, I can't install the virtual machine, it said can't get the software disk. I copied the Centos-7.ios from Ningbo Office. And it was okay to do.
2. I can't get the visual interface from tb15-6, the connection by using VNC to tb15-6 is successful, but since gnome is not installed I can't see anything.
3. Every time I virsh start virtual machine, I need to brctl addif br0. And when I configure the br0, the internet will be off or I still got the ERROR said "Cannot get interface MTU on 'br0': No such device". I am fixing that now.
4. When I use the virt-viewer to use the virtual machine, the mouse is easily get stuck. Fixing that too.
5. I have viewed the document which KVM official website linked: http://linux.dell.com/files/whitepapers/...http://linux.dell.com/files/whitepapers/KVM_Virtualization_in_RHEL_7_Made And try to learn more.

When you meet the mouse cannot use in the virtual machine, you can use the below code to fix:
Code:
#virsh edit <virtual machine name>.xml

Change the below statement which locate in label <devices>
Code:
<input type='mouse' bus='ps2'/> to <input type=’tablet’ bus=’usb’/>
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06-22-2018, 05:27 PM
Post: #9
RE: KVM behaviour
When I want to improve the Network performance, I am trying to use virtio to make network card para-virtualization.
At first we need to find out if our computer support virtio by using
Code:
grep -i Virtio /boot/config-3.10.0-327.el7.x86_64
shows like:
Code:
CONFIG_VIRTIO_BLK=m
CONFIG_SCSI_VIRTIO=m
CONFIG_VIRTIO_NET=m
CONFIG_VIRTIO_CONSOLE=m
CONFIG_HW_RANDOM_VIRTIO=m
CONFIG_VIRTIO=m
# Virtio drivers
CONFIG_VIRTIO_PCI=m
CONFIG_VIRTIO_PCI_LEGACY=y
CONFIG_VIRTIO_BALLOON=m
CONFIG_VIRTIO_INPUT=m
# CONFIG_VIRTIO_MMIO is not set
then add "<model type='virtio'/>" and "<driver name="vhost"/>" in your virtual machine XML file, like below:
Code:
<interface type='bridge'>
      <mac address='52:54:00:fb:ea:29'/>
      <source bridge='br0'/>
      <model type='virtio'/>
      <driver name='vhost'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>


and I am going to use "./speedtest-cli/speedtest.py" and "ping " to test the networks performance. But these methods have low accuracy. If I find another better way I will post it out.

RR Rayluk
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06-22-2018, 05:57 PM
Post: #10
RE: KVM behaviour
(06-22-2018 05:27 PM)changxy Wrote:  When I want to improve the Network performance, I am trying to use virtio to make network card para-virtualization.
At first we need to find out if our computer support virtio by using
Code:
grep -i Virtio /boot/config-3.10.0-327.el7.x86_64
shows like:
Code:
CONFIG_VIRTIO_BLK=m
CONFIG_SCSI_VIRTIO=m
CONFIG_VIRTIO_NET=m
CONFIG_VIRTIO_CONSOLE=m
CONFIG_HW_RANDOM_VIRTIO=m
CONFIG_VIRTIO=m
# Virtio drivers
CONFIG_VIRTIO_PCI=m
CONFIG_VIRTIO_PCI_LEGACY=y
CONFIG_VIRTIO_BALLOON=m
CONFIG_VIRTIO_INPUT=m
# CONFIG_VIRTIO_MMIO is not set
then add "<model type='virtio'/>" and "<driver name="vhost"/>" in your virtual machine XML file, like below:
Code:
<interface type='bridge'>
      <mac address='52:54:00:fb:ea:29'/>
      <source bridge='br0'/>
      <model type='virtio'/>
      <driver name='vhost'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>


and I am going to use "./speedtest-cli/speedtest.py" and "ping " to test the networks performance. But these methods have low accuracy. If I find another better way I will post it out.

RR Rayluk

for network performace, please use BasicTCP to test

BTW, I think you are still using vir-* for kvm. Its fine to use it as long as you are sure that it can be used on a remote machine.

Else is good to me.
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