10 Must See VSAN Sessions @ VMworld US

VMworld 2016 is only a few weeks away and once again it promises to be a HUGE event. I know many of the presenters are working on some awesome content and just maybe a few surprises. We will have plenty of stands, demos and a huge number of sessions to attend and be part of.

11220061_10152987425872691_8685634898144618972_nVirtual SAN Booth (2015)

If you are a VSAN customer, partner or just interested to learn more here is my list of non-negotiable sessions I would be adding to my schedule (in no particular order).

A Day in the Life of a VSAN I/O [STO7875]
Duncan Epping, Chief Technologist, VMware
John Nicholson, Senior Technical Marketing Manager, VMware

Virtual SAN – Day 2 Operations [STO7534]
Cormac Hogan, Senior Staff Engineer, VMware
Paudie ORiordan, Staff Engineer, VMware

VSAN Networking Deep Dive and Best Practices [STO8165R]
John Nicholson, Senior Technical Marketing Manager, VMware
Ankur Pai, Sr Manager VSAN R&D, VMware

Extreme Performance Series: Virtual SAN Performance Troubleshooting [STO8743]
Zach Shen, Sr. MTS, VMware, Inc.
Ruijin Zhou, Member of Technical Staff, VMware Inc.

Evolution of VMware Virtual SAN [STO9058]
Christos Karamanolis, VMware Fellow – CTO of Storage and Availability, VMware
Vijay Ramachandran, Sr. Dir Product Management, VMware

Virtual SAN Management Current & Future [STO7904]
Christian Dickmann, VSAN Architect, VMware

Virtual SAN: Introducing the Best HCI Platform for Containers and Cloud-Native Applications [STO8256]
Christian Dickmann, VSAN Architect, VMware
Rawlinson Rivera, Principal Architect Office of CTO – SABU, VMware, Inc

An Industry Roadmap: From storage to data management [STO7903]
Christos Karamanolis, VMware Fellow – CTO of Storage and Availability, VMware

The Future is Here: Turbocharge All Flash Virtual SAN with Next Generation Hardware [STO7953]
Bhumik Patel, Partner Architect, VMware
Rakesh Radhakrishnan, Product Management & Strategy Leader, VMware

Rawlinson Rivera, Principal Architect Office of CTO – SABU, VMware, Inc
John Whitman, Sr. Systems Engineer, VMware

There are many other great VSAN sessions so you’re sure to find something that takes your fancy if these don’t. The full content catalog can be viewed here http://www.vmworld.com/uscatalog.jspa if you are registered.

Do you have an interesting story to share or a question? we’d love to speak to you if you come by the VSAN booth. We’ll be there the entire event.

VSAN Power Outage

These days speaking with customers they like to discuss all the operational impacts and failure scenarios when deciding on Virtual SAN. Things such as, what happens when a disk fails, a controller, a node, a network etc. In some instances customers even asked what happens if all of my nodes fail at once, perhaps fearing data loss or corruption or problems when power is restored. This is absolutely NOT the case and does not occur. Read on.

Every quarter there is a scheduled power outage in our building and as such we have to go through a process of powering down the lab and powering it back on.


Fortunately, we have a pretty good process for managing this by now and it’s pretty simple. On occasions when I’ve been travelling I haven’t had the opportunity to shut the lab VSAN lab down gracefully and to this day it’s never caused me an issue.

My little lab is modest and runs on 3 Dell R720 servers and I just did an in-place upgrade using VMware Update Manager to vSphere 6.0U1a (VSAN 6.1) this week for all the latest goodies. I am not running an Active-Active type VSAN Stretched Cluster (more on that here) in my work lab so I need to deal with localised outages as efficiently as I can.

It was late afternoon on the Friday and I received a reminder of the impending power outage. I quickly took a screenshot of the current lab as it was running at that time and decided to ease my way into the weekend and let fate take over.


Lab Screenshot – Prior to shutdown (Friday 2pm)

Fast forward, Monday morning. I entered the server room to check my servers had powered on. I sat down at my desk and checked to ensure vCenter had come back up as it is configured to do. I logged into the vSphere Web Client to find the environment in perfect health and my virtual machines in a healthy state.

Screen Shot 2015-11-23 at 10.43.31 AM

Lab Screenshot (Monday 10am)

I also used the VSAN Health Plugin to check the  data and object health for any weirdness. Everything seemed compliant and healthy. Happy Days! Just to be sure you can see the timeline in the Events tab.

Screen Shot 2015-11-23 at 11.04.13 AM

So with VSAN we are able to provide crash consistency for the virtual machines and all IO that has reached the cache tier is held persistently until the cluster comes back to a normal health status and de-staging may be required. I logged in quickly to a few Windows and Linux guest machines to see if they were all healthy and discovered no issues.

As you can see, VSAN worked as designed and as I stated before this has happened on several occasions over the course of the last 2 years and I am yet to experience a problem on return, this time I thought I’d share it with you. It’s actually pretty boring, but I’d argue that’s the best way to deal with major power outages and/or hardware failures.

The best thing I could point you to for understanding failure impact and troubleshooting on VSAN is a very comprehensive document we published called the VSAN Troubleshooting Reference Guide found here VSAN Troubleshooting Reference Manual – VMware.