vSphere 4 Vmxnet3 Adapter
vSphere 4 Vmxnet3 Adapter – The Real (and Virtual) Adventures of Nathan the IT Guy
So you think you know Vmware, you have recently upgraded to vSphere 4.0 and you provision a new virtual machine, using the standard E1000 Nick (basically an Intel Pro 1000 Network Interface Card), you have bound 4 1Gb Nics to the virtual switch that the VM is on, so basically, your OS will only get 1Gb max through-put. Want more? That’s easy, bind a vmxnet3 adapter to the vm and you will now open up that pipe.
Question: What is VMXNET3?
Answer: VMXNET3 builds upon VMXNET and Enhanced VMXNET as the third generation paravirtualized virtual networking NIC for guest operating systems.
The VMXNET3 network adapter is a 10Gb virtual nic, with cards bound to it, you basically give that vm access to 4Gb of through-put, and if you attach more physical nics, you just keep increasing the through-put. With todays technology, server to workstation(1Gb Nic) file transfers are up to 60MB/sec!
Check out this link, to get the full scoop.
http://linuxhunt.blogspot.com/2010/03/vmxnet3-new-para-virtualized-nic-from.html
vmxnet3 :A New Para-Virtualized NIC from Vmware
VMXNET3, the newest generation of virtual network adapter from VMware, offers performance on par with or better than its previous generations in both Windows and Linux guests. Both the driver and the device have been highly tuned to perform better on modern systems. Furthermore, VMXNET3 introduces new features and enhancements, such as TSO6 and RSS.
TSO6 makes it especially useful for users deploying applications that deal with IPv6 traffic, while RSS is helpful for deployments requiring high scalability. All these features give VMXNET3 advantages that are not possible with previous generations of virtual network adapters.
Moving forward, to keep pace with an ever‐increasing demand for network bandwidth, Vmware recommend customers migrate to VMXNET3 if performance is of top concern to their deployments.
The VMXNET3 driver is NAPI‐compliant on Linux guests. NAPI is an interrupt mitigation mechanism that improves high‐speed networking performance on Linux by switching back and forth between interrupt mode and polling mode during packet receive. It is a proven technique to improve CPU efficiency and allows the
guest to process higher packet loads. VMXNET3 also supports Large Receive Offload (LRO) on Linux guests.However, in ESX 4.0 the VMkernel backend supports large receive packets only if the packets originate from another virtual machine running on the same host.
VMXNET3 supports larger Tx/Rx ring buffer sizes compared to previous generations of virtual network devices. This feature benefits certain network workloads with bursty and high‐peak throughput. Having a larger ring size provides extra buffering to better cope with transient packet bursts.
VMXNET3 supports three interrupt modes:
MSI‐X,
MSI, and
INTx.
Normally the VMXNET3 guest driver will attempt to use the interrupt modes in the order given above, if the guest kernel supports them. With VMXNET3, TCP Segmentation Offload (TSO) for IPv6 is supported for both Windows and Linux guests now, and TSO support for IPv4 is added for Solaris guests in addition to Windows and Linux guests.
To use VMXNET3, the user must install VMware Tools on a virtual machine with hardware version 7.
Good site: http://linuxhunt.blogspot.com/
about Linux in general and a few bits about VMware products too!
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