Cool tool update: RVTools 3.6

It has been a while since I reported an update of RVTools. Rob just emailed me and told me that Version 3.6 is available as of today. He has been working really hard to get some great new functionality in, which I am sure all of you will appreciate. One of the coolest free tools out there if you ask me! Great work again Rob, thanks for contributing to the community like this.

Version 3.6 (February, 2014)

  • New tabpage with cluster information
  • New tabpage with multipath information
  • On vInfo tabpage new fields HA Isolation response and HA restart priority
  • On vInfo tabpage new fields Cluster affinity rule information
  • On vInfo tabpage new fields connection state and suspend time
  • On vInfo tabpage new field The vSphere HA protection state for a virtual machine (DAS Protection)
  • On vInfo tabpage new field quest state.
  • On vCPU tabpage new fields Hot Add and Hot Remove information
  • On vCPU tabpage cpu/socket/cores information adapted
  • On vHost tabpage new fields VMotion support and storage VMotion support
  • On vMemory tabpage new field Hot Add
  • On vNetwork tabpage new field VM folder.
  • On vSC_VMK tabpage new field MTU
  • RVToolsSendMail: you can now also set the mail subject
  • Fixed a datastore bug for ESX version 3.5
  • Fixed a vmFolder bug when started from the commandline
  • Improved documentation for the commandline options

Serve, Learn and Inspire – support the cause and donate/contribute!

Today I am flying out to Vietnam. No not for a holiday, as many seem to think. I am flying out to Vietnam to work with several great VMware colleagues whom have been asked by the VMware Foundation to go on this journey. I am very grateful and honored to have been selected for this project, it is not just a random project… We will be helping Team4tech and Orphanimpact by working on improving the delivery of computer classes to various orphanages in Vietnam.

Some of you will probably have the same question as my daughter had when I explained why I was going away for almost 2 weeks to Vietnam: “You are going to an orphanage to do what… improve delivery of computer classes, why would those kids need that?” Watch this video and you will understand why it is important for these kids to get computer classes, preventing social isolation is key here.

More details about Orphan Impact here:
More details about Team4Tech here:

If your company is interested in contributing / giving back, make sure to contact Team4Tech and Orphan Impact. They work with many great technology companies like Intel and VMware on various projects, and they can use all the help they need.

I know many of my fellow technology lovers have a big heart. I would like to ask each and everyone of you who has enjoyed reading my articles to donate something to either Team4Tech or Orphan Impact. (Of course contributions in different ways like I describe above are also encouraged!) Believe me, this is a great cause and they can use all the help they can get. You (or the company your work for) can donate any amount, but with only 10 dollars you can give these kids a headphone for their computer classes for instance. (Before anyone asks, yes I just donated.) VMware folks, if you donate don’t forget to request a donation match through the VMware Foundation!

Support the cause!

Don’t create a Frankencluster just because you can…

In the last couple of weeks I have had various discussions around creating imbalanced clusters. Imbalanced from either CPU, memory and even a storage point of view. This typically comes up in discussions where either someone wants to bring larger scale to their cluster and they want to add hosts with more resources of any of the before mentioned types. Or also when licensing costs need to be limited and people want to restrict certain VMs to run a specific set of hosts. Something that comes up often when people are starting to look at virtualizing Oracle. (Andrew Mitchell published this excellent article on the topic of Oracle Licensing and soft vs hard partitioning which is worth reading!)

Why am I not a fan of imbalanced clusters when it comes to compute or storage resources? Why am I not a fan of crippling your environment purposely to ensure your VMs will only run on a subset of vSphere hosts? The reason is simple, the problems I have seen and experienced and the inefficiency in certain scenarios. Lets look at some examples:

Lets assume I have 4 hosts with each 128GB of memory. I need more memory in my cluster and I add a host with 256GB of memory. Now you just went from 512Gb to 768GB which is a huge increase. However, this is only true when you don’t do any form of admission control and resource management. When you do proper resource management or admission control than you would need to make sure that all of your virtual machines can run in the case of a failure, and preferably run with equal performance before and after the failure has occured. If you added 256GB of memory and this is being used and that host containing 256GB goes down your virtual machines could potentially be impacted. They might not restart, and if they restart they may not get the same amount of resources as they received before the failure. This scenario also applies to CPU, if you create an imbalance .

Another one I encountered recently was presenting a LUN to a limited set of hosts, in this case a LUN was only presented to 2 hosts out of the 20 hosts in that cluster… Guess what, when those two hosts die… so do your VMs. Not optimal right when they are running an Oracle database for instance. On top of that I have seen people pitching a VSAN cluster of 16 nodes with only 3 hosts contributing storage. Yes you can do that, but again… when things go bad, they will go horribly bad. Just imagine 1 host fails, how will you rebuild your components that were impacted? What is the performance impact? Very difficult to predict how it will impact your workload, so just keep it simple. Sure there is a cost overhead associated with separating workloads and creating dedicated clusters, but it will be easier to manage and more predictable in failure scenarios.

I guess in summary: If you want predictability in terms of availability and recoverability of your virtual machines go for a balanced environment, don’t create a Frankencluster!

What is Virtual SAN really about?

When talking about Virtual SAN you hear a lot of people talking about the benefits, what Virtual SAN is essentially about. You see the same with various other so-called Software Defined Storage solutions. People typically, when talking about these solutions, talk about things like “enabling within 2 clicks”… Or maybe about how easy it is to scale out, or scale-up for that matter. How much performance you have because of the way they use flash drives. Or about some of the advanced data services they offer.

While all of these are important, when it comes to Virtual SAN I don’t think that is the true strength. Sure, it is great to be able to provide a well performing easy to install scale-out storage solution… but the true strength in my opinion is: Policy Based Management & Integration. After having worked with VSAN for months, that is probably what stood out the most… policy based management

What does this deep integration and what do these policies allow you to do?

  • It provides the ability to specify both Performance and Availability characteristics using the UI (Web Client) or through the API.
    • Number of replicas
    • Stripe width
    • Cache reservations
    • Space reservations
  • It allows you to apply policies to your workload in an easy way through the UI (or API).
  • It provides the ability to do this in a granular way, per VMDK and not per datastore.
  • To a group of VMs or even all VMs in a programmatic way when needed.

Over the last couple of months I have played extensively with this feature of VSAN and vCenter, and in my opinion it is by far the biggest benefit of a hypervisor-converged storage solution. Deep integration with the platform, exposed in a simplistic VM-centric way through the Web Client and/or the vSphere APIs.

vSphere Availability Survey, please help out!

Just received the below from the vSphere Availability team. It takes a couple of minutes to fill out and it helps the vSphere Availability team to set priorities correctly for upcoming releases, yes indeed based on your answers!

— copy / paste —

The Availability team (that brings to you products such as vSphere HA, FT etc.) would like to get your input on how you use our products today and your projected needs. The survey has mainly multiple choice questions, and will take 10-15 minutes to complete. Your feedback is invaluable in helping us tailor our development efforts towards valuable enhancements. So, thank you!

Here’s the link to the survey: