VMDirectPath I/O allows a guest operating system on a virtual machine to directly access physical PCI and PCIe devices connected to a host. Each virtual machine can be connected to up to two PCI devices. PCI devices connected to a host can be marked as available for passthrough from the Hardware Advanced Settings in the Configuration tab for the host.
VMDirectPath allows guest operating systems to directly access an I/O device, bypassing the virtualization layer. This direct path, or passthrough can improve performance for VMware ESXTM systems that utilize high‐speed I/O devices, such as 10 Gigabit Ethernet.
VMware unveils VMDirectPath technology, Intel to support it with Nehalem:
Note that the VMware HCL describes servers, which are compatible to DirectPath - however the HCL does not document adapters, which can be used with this technology.
The "Configuration Examples and Troubleshooting for VMDirectPath" document covers a number of adapters - but seems to be a bit outdated.
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Limitations
When using VMDirectPath you lose following features:
VMotion
Storage VMotion
FT
Device hot add
Suspend and resume
Record and replay
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USB virtualization
If your server has support for device pass-through you may be able to provide USB access to Virtual Machines:
Let me add, that the VMware HCL describes servers, which are compatible to DirectPath - however the HCL does not document adapters, which can be used with this technology.
The "Configuration Examples and Troubleshooting for VMDirectPath" document covers a number of adapters - but seems to be a bit outdated.
Do you know other sources for an updated list of VMDirectPath compatible adapters?
After the release of vSphere 5 we really need some updated info on this. Will we ever see a list with supported NICs and storage adapters (and other devices)? Is the storage part still experimental in vSphere 5?
