Scott Drummonds on Virtualization

PVSCSI and vmxnet3

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I heard a myth today that VMware did not support running vmxnet3 and PVSCSI in the same virtual machine.  I have talked with a dozen engineers on the subject since it came up this morning and all swear the drivers run great together.  The two drivers work on very different and unrelated stacks in the VMkernel.  There are no inter-dependencies of any sort between PVSCSI and vmxnet3.

I think this rumor sprung from our somewhat limited support of paravirtualized drivers in FT-protected virtual machines, which will be improved in a subsequent release.  And while most of you probably know that PVSCSI and vmxnet3 run together, I thought it worth a brief comment on this blog.  Myths are like cockroaches.  For every one you see there are hundreds hiding behind the walls.

PVSCSI and Low IO Workloads


Scott Sauer recently asked me a tough question on Twitter.  My roaming best practices talk includes the phrase “do not use PVSCSI for low-IO workloads”.  When Scott saw a VMware KB echoing my recommendation, he asked the obvious question: “Why?”  It took me a couple of days to get a sufficient answer.

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