Deleting a vSAN datastore

I am a big vSAN fan and use it in my own Home Lab for most of my VM’s (main exception being  VM’s used for backing up … they are on my QNAP fileserver connected via iSCSI). My vSAN cluster configuration is quite static and the only thing that might change in the near future is increasing the capacity by adding an additional ESXi host to the cluster.

Currently I am running with vSAN version 6.2 and since the environment is very stable and it is my “production” environment I don’t plan to upgrade to the latest and greatest version yet. Still, I do want to work with the newer versions and functions (like iSCSI target) to become familiar with them and stay up-to-date with my vSAN knowledge, so I have a test (virtual) vSphere 6.5 Cluster with vSAN 6.5 installed, currently in a 2-node (ROBO) setup with an additional witness appliance.

With the release of vSAN 6.6 (check out the release notes here) I wanted to upgrade my vSAN 6.5 environment. Actually I decided to create a new vSAN 6.6 cluster from scratch with my existing ESXi hosts, which means I first had to delete my existing vSAN 6.5 datastore.

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New vSphere 6.5 feature – DRS CPU Over-Commitment percentage

Over-commitment of resources is a well known feature of vSphere and allows you to use the available physical resources as efficient as possible, resulting in a possibly higher consolidation ratio (number of VM’s per ESXi host). This feature is especially interesting with regard to CPU resources, as this is a type of resource that has a very low average utilization in many server environments. Using overcommitment of CPU allows you for example to configure a number of VM’s on a host with a total of  let’s say 50 virtual CPU’s (vCPU’s) where the specific host only has 16 physical cores available. This is an example based on a general best practice to allow for a 3-to-1 overcommitment ratio (3x as many vCPU’s configured as available physical cores). Sometimes you might want to reduce this (if you have very CPU-intensive workload running on your hosts) or you could even decide to allow for a higher overcommitment ratio of 5-to-1 (for workload that uses relatively little CPU).

DRS (Distributed Resource Scheduler) is a feature of a vSphere cluster that makes sure that all workload (VM’s) running on all hosts in that cluster is provided with the resources it needs. Balancing the load within the cluster is done by using vMotion migration of VM’s from hosts that have relatively little resources to hosts where resources are more plentiful available.

Starting with vSphere 6.5 a new setting is available in DRS that allows you to configure the allowed CPU over-commitment ratio. If you enable this feature, you can configure a setting of up to 500% (a 5-to-1 over-commitment ratio).

Now … how does this work and does this have any impact on availability you may ask.

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VMware VCP certification questions

During the VMware courses I teach I often get questions about the way to get certified and stay certified as a VCP. This blog post will try to explain your options.

First of all you need to be aware that several VCP certifications exist. The “classic” VCP (which focuses on vSphere) is called VCP-DCV nowadays (DCV being short for DataCenter Virtualization) and for those focusing on other VMware product lines additional certifications exist (specifically VCP-DTM for Desktop and Mobility, VCP-NV for Network Virtualization and VCP-CMA for Cloud Management and Automation).
Although these other certifications do not focus on vSphere they still require people that want to achieve them to at least have a solid base knowledge of vSphere. Therefore VMware has created a Foundation exam that every individual that wants to earn their first VCP certification (any type) needs to pass in addition to passing the specific VCP exam.

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VMware Certification Manager

Recently VMware introduced the VMware Certification Manager website. Linked to your MyLearn account this portal gives you a very clear overview of your existing certifications (with expiration dates) and the history of exams you have taken in the past as well as a list of possibly expired certifications.

The portal also gives you access to logo material  related to your certification status, allows you to create .pdf versions of your certifcations and create transcripts which you can share through several social media (like sharing it on your website … check out my certification transcript for example).

Finally you will be able to check out any new VMware certifications you would like to pursue and the paths you can (need to ) take to achieve these.

Just go to and click the “Certification Manager” link on the right, provide your MyLearn credentials and see for yourself.

Happy certifying !


Cisco joins the HCI club

This week Cisco has introduced their Hyperconverged infrastructure (HCI) solution called HyperFlex (aka the HX Data Platform). The solution is a combination of Cisco UCS hardware (both server and networking components), VMware vSphere software as the hypervisor layer and the Springpath Data Platform software as the (converged) storage layer.

The latter is a relatively new player in the HCI market and only recently came out of stealth (I wrote about it last year). Since currently the Springpath software only supports VMware, both HX models that were announced come with ESXi pre-installed. In the future Springpath is expected to also support other hypervisors (Hyper-V and KVM were already mentioned), so probably other HX models will be available in the future as well.

Although based on the existing UCS hardware, the Cisco HyperFlex solution exists only as a completely pre-configured system. It is not possible to “build-you-own” HyperFlex system. Of course with a combination of Cisco UCS, VMware vSphere and Springpath you can create a system that is very similar to the pre-built configurations, but the advantage of the  Cisco HyperFlex solution is that you only need to deal with a single support contact. Also by only supporting the pre-built configuration Cisco is better able to guarantee performance levels. This approach looks similar to Nutanix, which basically is a software product, but only sells it as a solution packaged with server and storage components.

Cisco differentiates itself however by also including the networking stack into the solution. Again this is mainly an advantage with regard to ease of support, as I guess that in many environments where HCI is installed, the networking part is also taken care of by Cisco components.

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Installing the ESXi Host Client (Tech Preview)

Some time ago I came across a neat little “Fling” on the VMware labs site (a collection of tools built by VMware engineers) called the ESXi Host Client. When installed in your stand-alone ESXi host you will be able to manage the host through a web browser instead of having to use the traditional vSphere Client. Although the status of this piece of software is “Tech Preview”, so it is not officially supported by VMware for production environments, it is already very complete and easy to use. Recently the host client presented me a popup suggesting I look at the fling website to check whether a newer version was already available … and it was. So I went ahead, downloaded the software and installed it. In this case I first removed the old version by logging in to the ESXi console and using the command :

esxcli software vib remove -n esx-ui

The procedure to install the host client is pretty straightforward and is described below.

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VMware Virtual SAN Announcements

This week was an exciting week for VMware Virtual SAN enthusiasts (of which I am one). I’m looking forward to checking out the new features and functions as they become available with version 6.2 (VMware stated this would be by the end of the quarter). With these features the Virtual SAN solution becomes quite a mature storage solution comparable in feature set with many traditional (SAN/NAS) midrange storage systems. Among the features that will become available with the core product are :

  • Checksumming … making data integrity more robust
  • IOPS limits per object … improving Storage based QoS
  • Deploying thin swap objects … decreasing the overhead required for swapping (which you would want to prevent anyway)
  • Improved Virtual SAN management capabilities in the WebClient … removing the need for additional (RVC based) tools

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VMware Advanced Professional (VCAP) certification not going away

With the introduction of vSphere 6.0 VMware introduced a new level of certification called VCIX6-DCV (with “IX” standing for “Implementation eXpert”). In order to achieve this certification one needs to take two exams, focusing on Deployment and Design respectively. VMware has announced these two exams to be available early 2016 and they would be comparable to the former VCAP5-DCA and VCAP5-DCD exams.

Initially VMware had planned to retire these individual two certifications, replacing them with the single VCIX6-DCV certifications. Recently however VMware has announced that people will still be able to achieve these two Advanced Professional certifications for vSphere 6. Achieving both certifications will grant individuals the right to carry the VCIX6-DCV badge.

Anyone who already holds one of the two advanced certifcations for vSphere 5 can upgrade to VCIX6-DCV by taking the vSphere 6 version of the “other” exam (so take the Design exam if you hold the VCAP5-DCD or the Deployment exam if you hold the VCAP5-DCA).

VCIX6-DCV will be a requirement to move to the highest VMware certification level : VCDX6-DCV.

Springpath Hyperconverged Infrastructure

HyperConverged Infrastructure (HCI) is a hot topic these days. It’s promise is increased flexibility (agility) and scalability at a lower cost than infrastructures based on traditional shared storage (SAN/NAS) while retaining the functionality that we have become accustomed to (like snapshots, cloning and replication) and supporting most enterprise application environments.
Creating a hyperconverged infrastructure can be achieved very easily with the building block concept of companies like Nutanix and Simplivity. You can start very simple by creating a cluster of (usually) only 3 nodes and gradually increase the size of your infrastructure when required by simply adding nodes to the existing environment. The potential disadvantage of this (hardware) appliance-based approach is that you are usually limited in your choice of appliance configuration (amount of CPU, memory and type/capacity of storage devices). This means that you could end up with an infrastructure with too much CPU, too much memory or too much storage capacity (so too much investment …).

VMware Learning Zone (VLZ)

The VMware Learning Zone (VLZ) is a relatively new way for VMware to provide technical content around various VMware products. This is done through a series of videos presented by a selection of top consultants and trainers.
The content is available on a yearly subscription basis in the form of either a “Standard”or a “Premium” VLZ subscription. The latter also including Certification Exam Prep content (currently specifically for the VCP6-DCV certification).
Recently I have had the pleasure to check out the VLZ content and found the material to be very useful and of high quality. Currently the library contains around 70 videos about topics like vSphere, Virtual SAN, vROps, vCAC, Horizon, SRM and NSX. Content is being added on a regular basis (check out this blog for updates). Especially the exam prep part of the library still seems to be “work in progress” as many modules are lacking video content.
After subscribing to the VMware Learning Zone you will have access through the VMware learning system “MyLearn”. Once Logged in, you will find the VLZ subscription as a Self Paced course with access for 365 days under “MyEnrollments”. New content will automatically show up in the library and is free to be accessed as long as you have a valid subscription.
More information about the subscriptions and available video content check out the VMware education site.