VSAN – Page 21

How Wrecking Crew Inc. leveraged vSphere's Instant Clone to instantly provision hundreds of VMs

09.18.2015 by William Lam // 9 Comments

Okay, Wrecking Crew Inc. is not a real company but a fictitious one that was used during Alan Renouf and Li Zheng's VMworld session, #INF5803 - Deploy Hundreds of VMs Instantly via Forking (aka vSphere Instant Clone). During the session, Wrecking Crew Inc. was described as a modern online gaming company who was about to launch a new product. They found out that their game was going to be more popular than they had originally anticipated and needed to be able to quickly spin up a large number of instances of their game to handle the load.

Though this was a fictional company to help set the stage for the demo, the underlying use case is an actual challenge for many of our customers. One of the examples that Alan used was the traditional Black Friday sale which occurs on the Friday after Thanksgiving in US. As you can imagine, being able to quickly scale up your online application based on customer demand can really give retailers an real edge over their competition. In todays world, waiting a few additional seconds for a site to load can mean the difference between a sale and customer going else where for their business. Online retail is just one of the many industries and verticals that can easily benefit from the Instant Clone capability.

To help further demonstrate the use case, a recorded demo was shown utilizing the new PowerCLI Extensions which provides access to the Instant Clone feature from an Automation standpoint. I actually built the demo for Alan and Li's session and I thought I would share some more details along with the video in case you were not able to attend the session in person, which I was not able to do.

Below are the set of technologies that were used in the demo:

I wanted to also give a quick shoutout to my buddy Rawlinson Rivera for his help with Intel and getting us access to their 64 Node NVMe VSAN Cluster. Our friends over at Intel were kind enough to allow us to quickly record a demo before they had to pack and ship the hardware to San Francisco for VMworld.

To provide some additional context on what you will see in the video, a diagram is provided below. The environment initially consists of two Photon VMs which runs the Consul Cluster which provides service discovery and configuration capabilities and the Nginx Load Balancer which is highlighted in the purple and blue box. Each of those VMs run their respective application which runs inside of a Docker Container and is highlighted in the smaller boxes. On each ESXi host, we have Photon VM which contains our Node.js application that we will be Instant Cloning from. This Photon VM is also referred to as the Parent VM and where all the new forked children VMs will be spawn off of.

This Photon VM also runs an instance of Consul, Registrator and the Node.js application inside of a Docker Container. As new instances are brought online which is highlighted in the black box, they will automatically register themselves with the Consul Cluster. As the Docker Containers are started up, Registrator will be notified to automatically add the new instances to the Nginx Load Balancer, making our application servers available for use immediately. When our application server powers down, Registrator will automatically detect that the Docker Container for our Node.js application is no longer running and automatically unregister it from the Nginx Load Balancer. To simply scale up or down the application, it is simply Instant Cloning our Photon (Parent) VM and powering it on or off, there are no additional steps required.

Without further ado, here is the video of the demo. If you want additional commentary and you attended VMworld US but could not make it to Alan and Li's session, you can now watch it online here. This session will also be repeated in VMworld EMEA for those attending in a couple of weeks. I would highly recommend you check out the session as there is a lot of awesomeness in the session along with technical deep dive of the Instant Clone technology.

VMworld 2015 Demo of how Wrecking Crew Inc. leverages vSphere's Instant Clone feature from lamw on Vimeo.

For more details about Instant Clone, be sure to check out these resources below which includes a Instant Clone script repository for several GuestOSes, including Photon which was used in the demo:

Override default VSAN Maintenance (decommission) Mode in VSAN 6.1

09.14.2015 by William Lam // Leave a Comment

Earlier this year, there was an interesting use case that was brought up from a customer regarding the use of vSphere Update Manager (VUM) and VSAN enabled ESXi hosts. Everything was working from a functional standpoint, but the customer wanted a way to control the default VSAN decommission mode which specifies how the data should be moved, if at all when a host is placed into maintenance mode. There are three supported options which includes Ensure Accessibility (default), Evacuate All Data and No Action. Depending on the customer and their use case, there may be valid reasons to use one or the other. For example, if I am shutting down my entire VSAN cluster for some hardware upgrade, I probably do not want any of my data to be migrated and the No Action setting would be acceptable. During an upgrade or patching an of ESXi host, some customers have expressed that they would prefer to leverage the Evacuate All Data setting which is perfectly fine, of course the maintenance mode would take long as all the dat must be migrated off the host first.

Prior to VSAN 6.1 (included in the vSphere 6.0 Update 1 release), it was not possible to override the default VSAN maintenance mode (decommission mode) option which defaults to Ensure Accessibility. This was a problem because if you decided you wanted to use a different option, there would be some manual intervention required from the user when using VUM. The workaround for the customer would be to either manually or using the vSphere API to automate the ESXi host maintenance mode operation and specify the decommission mode type before VUM would take over and update the host. Not an ideal solution but would work if you needed to override the default.

I thought this would be a nice feature enhancement to be able to override the default VSAN maintenance mode option which could vary from customer to customer depending on their use case. I got in touch with one of the VSAN Engineers to discuss the use case in more detail and he agreed that it would be useful to expose this type of a capability. In VSAN 6.1, there is now a new ESXi Advanced Setting called DefaultHostDecommissionMode which allows you to specify the default VSAN maintenance mode behavior.

Below is a table of the three available options (ensureAccessibility is default) that can be configured:

VSAN Decommission Mode Value	Description
ensureAccessibility	VSAN data reconfiguration should be performed to ensure storage object accessibility
evacuateAllData	VSAN data evacuation should be performed such that all storage object data is removed from the host
noAction	No special action should take place regarding VSAN data

This ESXi Advanced Setting can also be retrieved and configured using ESXCLI as well as the vSphere API.

To retrieve the current VSAN maintenance mode option using ESXCLI, run the following command:

esxcli system settings advanced list -o /VSAN/DefaultHostDecommissionMode

To configure the default VSAN maintenance mode option using ESXCLI, run the following command:

esxcli system settings advanced set -o /VSAN/DefaultHostDecommissionMode -s [DECOMISSION_MODE]

How to deploy and run the VSAN 6.1 Witness Virtual Appliance on VMware Fusion & Workstation?

09.11.2015 by William Lam // 20 Comments

One of the most exciting new feature in VSAN 6.1 is the new Stretched Clustering capability which also provides support for a 2-Node ROBO deployment. If you are interested in learning more about the new VSAN 6.1 capabilities, be sure to check out Duncan's blog post here as well as a video on how to configure the new VSAN Stretched Clustering here. Like many of you, I am sure you are looking forward to giving both vSphere 6.0 Update 1 as well as the new VSAN 6.1 capabilities a spin in your home lab or development environment. By now, you probably know how easy it is to run Nested ESXi on top of your existing vSphere environment. However, not everyone has access to a vSphere environment. The next best thing is using VMware Fusion and Workstation which also supports Nested ESXi and for many of our customers and field, it is a great solution as it allows you to easily play with all the VMware goodies while you are on the go, especially useful if you travel frequently.

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