VM Feature Identification: Difference between revisions
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[ 0.000000] Xen: using vcpuop timer interface |
[ 0.000000] Xen: using vcpuop timer interface |
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If PV network drivers are in use, you might see: |
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[ 0.432488] Initialising Xen virtual ethernet driver. |
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Revision as of 16:47, 13 October 2014
When you control your own hypervisor, you are aware of the features you are using, since you have configured the system and the VMs. However, if you are using a service provider for your hosting or cloud, you need to do some detective work to determine the hypervisor mode and features employed.
MODE DETECTION
The output of the dmesg command contains many useful bits of information about the processor mode:
HVM-type:
If your VM is either HVM or PVHVM, look for:
[ 0.000000] Hypervisor detected: Xen HVM
PV-type:
If your VM is PV or PVH, look for:
[ 0.000000] Booting paravirtualized kernel on Xen
This message indicates that PV timers are in use:
[ 0.000000] Xen: using vcpuop timer interface
If PV network drivers are in use, you might see:
[ 0.432488] Initialising Xen virtual ethernet driver.
REFERENCES
- A truly great article by Brendan Gregg