Yellow Bricks

by Duncan Epping

vSphere

Booting ESXi from SD/USB devices? Time to reconsider when buying new hardware!

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We’ve all seen those posts from people about worn-out SD/USB devices, or maybe even experience it ourselves at some point in time. Most of you reading this probably also knew there was an issue with 7.0 U2, which resulted in USB/SD devices wearing out a lot quicker. Those issues have been resolved with the latest patch for 7.0 U2. It has, however, resulted in a longer debate around whether SD/USB devices should still be used for booting ESXi, and it seems that the jury has reached a verdict.

On the 16th of September, a KB article was published by VMware, which contains statements around the future of SD/USB devices. I can be short about it, if you are buying new hardware make sure to have a proper persistent storage device, USB/SD is not the right choice going forward! Why? The volume of reads/writes to and from the OS-DATA partition continues to increase with every release, which means that the lower grade devices will simply wear out faster. Now, I am not going to repeat word for word what is mentioned in the KB, I would just like to urge everyone to read the KB article, and make sure to plan accordingly! Personally, I am a fan of M.2 flash devices for booting. They are not too expensive(greenfield deployments), plus they can provide enterprise-grade persistent storage to store all your ESXi related data. Make sure to follow the requirements around endurance though!

My recommended sessions for VMworld 2021!

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It is that time of the year again, the VMworld content catalog has been posted online! Like every year I am going to provide a list of sessions that I highly recommend watching. There are many great sessions, and I can’t list them all, so I am going to limit it to 15 sessions again. If you feel there’s a great session missing, feel free to leave a comment of course! Oh and before I forget, I suspect that at the first day of the event multiple sessions will be added (new products/features/versions etc), so keep checking the content catalog during the event as well!

I have a session with Cormac titled: “VMware vSAN – Dynamic Volumes for Traditional and Modern Applications [MCL1084]”. We will be discussing how to use vSAN for VMs and Containers. Find it here.

In no particular order:

  • Project Monterey: Present, Future and Beyond [MCL1401] by Sudhanshu Jain and Simer Singh
    SmartNICs and DPUs have been talked about a lot at last years VMworld, and slowly we are starting to see more and more uptake of it amongst customers. If you are interested in what these accelerators can do for you today and tomorrow, make sure to check this session!
  • VMware’s Vision for Storage and Data in a Multi-Cloud World [MCL2505] by Marc Fleischmann and Vijay Ramachandran
    This has traditionally always been one of my favorite sessions about the future of Storage and Data. Why? Well, in this session Marc and Vijay will give insights into what you can expect from VMware in the near (and long term) future. Who doesn’t enjoy a roadmap!
  • Make Sustainable Choices for Product Innovation, Operations: What Can I Do? [IC2794] by Joe Baguley and Adrian Cockcroft
    Two powerhouses have teamed up, Adrian Cockcroft and Joe Baguley. Not just for this session, but they have another session around sustainability (IC2792). Not only an intriguing subject, but also something which is on top of many C-level execs today.
  • Core Storage Best Practices Deep Dive [MCL2071] by Jason Massae and Cody Hosterman
    This is a VMworld top 10 session literally every year for a reason. It has great content, it is deep technical, and it is delivered by great speakers. Must see!
  • Security Deep Dive and Emerging Capabilities in VMware Cloud on AWS [SEC1362] by Ron Fuller
    I haven’t seen any sessions by Ron just yet, but the title and the description just interest me. I think that security is still overlooked, and I think that for everyone it would be useful to learn about how security offerings are implemented in public cloud environments!
  • VEBA Revolutions – Unleashing the Power of Event-Driven Automation [CODE2773] by Michael Gasch and William Lam
    It took me a while to see where VEBA would be useful, but after it clicked I have recommended various folks to check out this event-driven way of automation to solve certain problems they were experiencing. Plus, Michael Gasch and William Lam means it will be deep and excellent!
  • VDI Nerdfest 2021: Demos That Make Admins Drool [EUS1289] by Johan van Amersfoort and Jon Towles
    This session last year was packed with great demos, this alone for me is a reason to watch it again this year. I always appreciate a great demo, something that has you thinking “how did they do that?”…
  • Extreme Performance Series: Performance best practices [MCL1635] by Mark A and Valentin Bondzio
    This one comes as both a session as well as a boot camp (MCL2033). This session will provide you the tools you need to do performance troubleshooting, or simply will provide you with a better understanding of all the different parts of the stack and where potential choking points could be.
  • 60 Minutes of Non-Uniform Memory Access (NUMA) 3rd Edition [MCL1853] by Frank Denneman
    Never attended this session and you call yourself a geek? SHAME!
  • Best Practices for Running AI Workloads in VMs on VMware vSphere [VI1459] by Justin Murray and Andrew Liu
    Justin delivered one of the best sessions in 2020 if you ask me, also on the topic of AI and GPUs, and I expect a lot of this joint session with NVIDIA’s Andrew Liu.
  • The Future of VM Provisioning – Enabling VM Lifecycle Through Kubernetes [APP1564] by Myles Gray and Nikitha Suryadevara
    Kubernetes is all about containerized apps! Could it be used for provisioning VMs? Myles and Nikitha will tell you all about it in this session. Interesting concept!
  • The Evolution of Intelligent Edge and Electrical Grid Modernization [VI1455] by Daniel Beveridge, Alan Renouf, and Prithpal Khajuria
    Daniel and Alan are part of the Office of CTO, and more specifically the innovation labs. That is why this session stood out. Combine it with the buzzwords “intelligent edge” and a co-speaker from Intel (Prithpal), and I am sure this session will spark conversations!
  • Upskill Your Workforce with Augmented and Virtual Reality and VMware [VI1596] by Alan Renouf and Matt Coppinger
    I worked on a project at the start of 2020 with Alan and Matt around virtualizing VR and AR workloads, very interesting stuff. Also interesting to hear about these different AR and VR use cases that enterprises have these days. Reminds me, I still need to pick up an Oculus Quest 2.
  • Automating Ransomware Remediation with the VMware Carbon Black Cloud SDK [CODE2782] by Alex van Brunt and Emanuela Mitreva
    Open up any website that discusses IT and you will most likely see one or two articles on the topic of ransomware. There’s a long list of sessions discussing what Carbon Black is at VMworld, but this one stood out to me as it discussed automating the remediation, which should be a crucial part of your plan to defend against attacks!
  • Migration in Action with Google Cloud VMware Engine [MCL1764] by Emad Younis and Simon Long
    Emad has a few sessions on the topic of multi-cloud workload migration and management, I had to pick one, so I picked this one where the migration to Google Cloud is discussed. Sounds like an interesting session, and both Emad and Simon are great presenters, so it should be good!
  • That was it for now, if more sessions are added to the catalog I may just do an update, probably after VMworld after I watched some of them. Anyway, now it is time to sign up for VMworld 2021! Let’s hope we can all attend “in-person” again next year.

iSCSI IQN may have changed after upgrade to 7.0 U2

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Last week I noticed some folks reporting that they had an issue with upgrades to 7.0 U2 from 7.0 U1. The issue they experienced was not being able to access their iSCSI Datastores any longer. I did some digging internally and found out there was a change in how we store the iSCSI IQN when the IQN is randomly created. Now note, this problem only exists for randomly created IQNs, so if you have a custom-named iSCSI IQN then you can stop reading here. If you have a random IQN and also have access control defined for your initiators, then you will want to read this if you are planning on upgrading.

Basically what happens if you upgrade from 7.0 U1 to 7.0U2 and you use a randomly generated IQN is that we regenerate the IQN after a reboot. What does that look like, well on VMTN user Nebb2k8 posted this:

7U1d = iqn.1998-01.com.vmware:labesx06-4ff17c83

7U2a = iqn.1998-01.com.vmware:labesx07:38717532:64

As you can see, the format also changed.

So if you lose (or lost) access after the upgrade, you simply copy the newly generated IQN and add it to the access control list of your storage system for the LUNs it applies to. Make sure to remove the old IQNs. Another option of course is to configure the randomly generated IQN as a custom IQN, this is pretty straightforward as shown below for “vmhba67”. You could create new IQNs, or you could re-use the randomly generated old IQNs if you want to keep them the same.

$ esxcli iscsi adapter get -A vmhba67

 vmhba67
   Name: iqn.1998-01.com.vmware:w1-hs3-n2503.eng.vmware.com:452738760:67

$ esxcli iscsi adapter set -A vmhba67 -n iqn.1998-01.com.vmware:w1-hs3-n2503.eng.vmware.com:452738760:67

If you would like to know more about this issue, make sure to read this KB article, or read this article by Jason Massae which also provides some PowerCLI code to get/set the IQN.

How do I change the name of a vSwitch with vSphere 7.0 U2 and higher?

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Some of you may have noticed it already, and some may not, but a lot of the configuration details that were traditionally stored in “esx.conf” have now moved elsewhere. The question is where did it go? Well it went into “configstore” and with “configstore” now also comes a commandline interface called “configstorecli”. I briefly mentioned this in a previous post a few weeks ago. Today I noticed a question on VMTN around renaming a vswitch on a host and how you can do this now that the vswitch details have disappeared from esx.conf.

I figured I should be able to test this in my lab and write a short howto. So here we go.

You can look at the current network configuration for your vSwitch using the following command:

configstorecli config current get -c esx -g network_vss -k switches

Then what you can do is dump the info in a json file, which you will then be able to edit:

configstorecli config current get -c esx -g network_vss -k switches > vswitch.json

The file will look something like this:

After you made the required changes, you then load the configuration using the json file:

configstorecli config current set -c esx -g network_vss -k switches -i vswitch.json --overwrite

I changed the name of my vSwitch0 to “vSwitchDuncan” and as you can see below, the change worked! Although do note, you will need to reboot the host before you see the change!

For those who prefer video content, I also created a quick demo which shows the above process:

Can I make a host in a cluster the vSphere HA primary / master host?

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There was an interesting question on the VMware VMTN Community this week, although I wrote about this in 2016 I figured I would do a short write-up again as the procedure changed since 7.0u1. The question was if it was possible to make a particular host in a cluster the vSphere HA primary (or master as it was called previously) host. The use case was pretty straightforward, in this case, the customer had a stretched cluster configuration with vSAN, they wanted to make sure that the vSphere HA primary host was located in the “preferred” site, as this could potentially speed up the restart of VMs. Now, mind you, that when I say “speed up” we are talking about 2-3 seconds difference at most, but for some folks, this may be crucial. I personally would not recommend making configuration changes, but if you do want to do this, vSphere does have the option to do so.

When it comes to vSphere HA, there’s no UI option or anything like that to assign the “primary/master” host role. However, there’s the option to specify an advanced setting on a host level to indicate that a certain host needs to be favored during the primary/master election. Again, this is not very common for customers to configure, but if you desire to do so, it is possible. The advanced setting is called “fdm.nodeGoodness” and depending on which version you use, you will need to configure it either via the fdm.cfg file, or via the configstorecli. You can read about this process in-depth here.

Of course, I did try if this worked in my lab, here’s what I did, I first list the current configured advanced options using configstorecli for vSphere HA:

configstorecli config current get -g cluster -c ha -k fdm
{
   "mem_reservation_MB": 200,
   "memory_checker_time_in_secs": 0
}

Next, I will set the “node_goodness” for my host, when setting this it will need to be a positive value, in my case I am setting it to 10000000. I first dumped the current config in a json file:

configstorecli config current get -g cluster -c ha -k fdm > test.json

Next, I edited the file and added the setting “node_goodness” with a value of 10000000, so that is looks as follows:

{ 
    "mem_reservation_MB": 200, 
    "memory_checker_time_in_secs": 0,
    "node_goodness": 10000000
}

I then imported the file:

configstorecli config current set -g cluster -c ha -k fdm -infile test.json

After importing the file and reconfiguring for HA on one of my hosts, you can see in the screenshots below that the master role moved from 1507 to 1505.


I also created a quick demo, for those who prefer video content: