Turkey Day Mailbag

Hello Networking Enthusiasts – Tomorrow, the US will celebrate Thanksgiving and since we’re so close to a holiday we decided to keep this week’s blog fairly simple and answer some common questions and information we’ve seen over the last few months.

If you have follow-up questions you’d like answered (or more details on what’s below), hit us up on Twitter @ Microsoft SDN!

RDMA and HCI

Q. Network traffic from Live Migrations takes valuable CPU cycles from my tenant VMs. How can I reduce the impact of a live migration for tenants, increase the number of live migrations I can perform, and/or increase the speed of the live migrations?

Answer from RDMA PM, Dan Cuomo:

Although not the default option, SMB can be selected as the live migration mechanism.  If selected, SMB can use RDMA under the hood (in this context, known as SMBDirect), which avoids the need to process the GB’s (yes, Gigabytes not bits) of network traffic produced from the live migration (e.g VM Memory or VHDX Storage).

RDMA by-passes the host operating system and removes the processing burden of the live migrations.  Since host networking is most commonly constrained by host CPU spreading (remember your VMs are competing for access to the same cores processing network traffic), RDMA eases the effect of the live migration on VMs on the same host as they can now continue to focus on the VMs CPU scheduling needs.

The net effect is an increase to the number of live migrations you can perform at once because the CPU is no longer the bottleneck for the network or affecting your tenant VMs.

Software Defined Networking

Q. How do I get support deploying Software Define Networking?

Answer from SDN PM, Schumann Ge
There are a ton of resources available and we’d recommend you’d start with our documentation here.  However if you’d like to speak to an expert, our field engineers would be glad to assist.  Contact them at SDNBlackbelt@Microsoft.com or hit-up Microsoft SDN on twitter!

Containers

Q. Does Red Hat OpenShift support Windows Containers?  Where can I find out more about Red Hat OpenShift?  What is the roadmap of supporting Windows Containers with Kubernetes?

We’re posting this answer from Containers PM, Mike Kosteritz under protest because it’s technically three questions…
See the blog post “Managing Windows containers with Red Hat OpenShift Container Platform 3.11” for an overview what is coming in this space.

General information on OpenShift is available on the https://www.openshift.com/products website. If you have Windows specific questions please post a comment to the blog post at “Managing Windows containers with Red Hat OpenShift Container Platform 3.11

Networking Diagnosis Tools

Q. How do I review all the pertinent Networking information on my system.  I’m not sure I know all the cmdlet’s I need or how to put the data together into a cohesive view of my system.

Answer from Datapath PM, Dan Cuomo:
Get-NetView is a nifty script that curates all the pertinent networking information into a single zip file for portability.  It even grabs the data about the VMs sitting on system.  If you’re one of the many customer’s we’ve worked with over the last year or so, you’ve no doubt had to run this command and send us the output for review.  Also, this tool is integrated into Get-SDDCDiagnosticInfo cmdlet you’ve no doubt run when troubleshooting Storage Spaces Direct.

Once extracted to a folder, we’d recommend using Visual Studio Code for review of the contents of the folder.  Check out Get-NetView on GitHub

Happy Turkey Day,
Windows Core Networking Team