Getting started with CoreOS on Nutanix Community Edition

24 07 2015

Containers seem to be the hot trend right now. I needed to get some more experience in this area, and instead of working with a single container machine, I actually wanted to get a “quick” distributed setup going. It wasn’t all that quick to start with, but I now have a working setup that can actually be rolled out and scaled in a pretty quick fashion.

Now, I’m assuming you already know what a container is, and have heard about CoreOS. Here are some quick steps to get you started. I’ll start off with the prerequisites:

  • You will have your Nutanix CE cluster up and running
  • You have a VLAN set up with IP address management and a DHCP server on Nutanix CE
  • You downloaded the CoreOS ISO image

Your further steps are relatively simple. First off, we will create an etcd master, the most important thing we need is a fixed IP, so define which IP you want to give it. Obviously we could use the CoreOS cluster discovery mechanism and rely on an internet connection, but I decided to just use my own instance instead.

Start off by creating a cloud-config file for your etcd master:

  - ssh-rsa AAAAB3NzaC1...
    name: etcdserver
    initial-cluster: etcdserver=http://<etcd-vm-ip-here>:2380
    initial-advertise-peer-urls: http://<etcd-vm-ip-here>:2380
    advertise-client-urls: http://<etcd-vm-ip-here>:2379
    # listen on both the official ports and the legacy ports
    # legacy ports can be omitted if your application doesn't depend on them
    - name: etcd2.service
    command: start
    - name:
    runtime: true
    content: |

Note that I’ve copied in the public ssh key from my laptop to get easier access to the VM. Now, save this file as a text file called user_data, and create an iso image using the ways described here. Copy that over to your container on CE using sftp to a controller VM on port 2222. You can use Prism credentials to authenticate.

Next step, create a new VM in Acropolis, attach the CoreOS ISO image as your primary CD drive, and the ISO you just created as the second CD drive, and power on the VM

Now, to create the actual CoreOS cluster, you create a second user_data file, that only contains the following:

 - ssh-rsa AAAAB3NzaC1...
    proxy: on
    initial-cluster: etcdserver=http://<etcd-vm-ip-here>:2380
    listen-client-urls: http://localhost:2379
    etcd_servers: http://localhost:2379
    metadata: "role=etcd"
    - name: etcd2.service
    command: start
    - name: fleet.service
    command: start

For quick deployment, I’d create a VM that you use as a template to clone from. Give the VM the newly created file as the secondary drive.

Now, just create some clones, power them on and wait for them to get their IP. You should then be able to ssh into the machine using the “core” user, and check your cluster:

core@CoreOS-1 ~ $ fleetctl list-machines
MACHINE     IP             METADATA
1c24fc23... role=etcd
8e974c05...  role=etcd
a899b944...  role=etcd
f916eb93...  role=etcd

With that, you can start implementing and rolling out your units:

core@CoreOS-1 ~ $ fleetctl load hello.service
Unit hello.service loaded on 1c24fc23.../

core@CoreOS-1 ~ $ fleetctl list-units
UNIT          MACHINE                    ACTIVE   SUB
hello.service 1c24fc23.../ inactive dead

Nutanix OS 4.0 – Prism Central

17 04 2014

One of the features that has been announced for Nutanix OS 4.0 (also called NOS), is something called Prism Central.

So what does Prism Central do? Well, perhaps things are more obvious if we speak about the internal name we once used. It was referenced as our Multi-Cluster UI, and that is exactly what it is. Instead of having to open multiple tabs in your browser and switching between tabs to actually manage your Nutanix clusters, you can now open one tab, register multiple clusters, and manage them all from one interface, or get a basic overview of what is going on across all clusters.

First things first: Disclaimer – Keep in mind this is based on an early code version, and things will most likely change before you can download the software.

I spoke to our developers, and received a version to play with, so I’ll walk you through the process. Prism Central comes as an OVF, and you simply deploy this VM in your infrastructure. The requirements for the VM are the following (again, this might change):

2 vCPUs
260GB disk space

With that configuration, you can monitor 100 nodes while we assume that you can go up to 100 VMs per node.

With that said, the installation itself is quite easy. We deploy the OVF from vCenter:

Prism Central - OVF Deployment

Prism Central – OVF Deployment

We give the VM a name:

Prism Central - OVF Deployment - Naming

Prism Central – OVF Deployment – Naming

And follow the normal steps for any OVF. Things like selecting a resource pool, datastore, and then selecting the disk format and network mapping. You will only need one interface, but I’d recommend deploying the Prism Central VM in the same network as your controller VMs. Once that is done, you click on “Finish” and wait for the VM to deploy:

Prism Central - OVF Deployment - Finished

Prism Central – OVF Deployment – Finished

Now, my assumption is that we will be changing to the OVA format to make deployment a bit easier. In this version, I still had to configure the IP addresses manually (no DHCP in my network), and deploying from an OVA should make that a breeze, but I will outline the steps I used here anyway.

After connecting to the vSphere console of the VM, we log on to the console using “nutanix” as the user and “nutanix/4u” as the password. Then, you simply edit the file /etc/sysconfig/network-scripts/ifcfg-eth0 and input the IP-address you would like to use. In my case it looks like this:


Simply save the file and restart your network services, and you should now be able to access the machine using your favorite ssh client. Now there is one thing left to do (and again, I’m assuming this should no longer be there in a final release, just trying to be complete):

cluster -f --cluster_function_list="multicluster" -s ip_of_your_prism_central create

Which should result in something like this:
nutanix@NTNX-10-64-20-110-A-CVM:~$ cluster -f --cluster_function_list="multicluster" -s create
2014-04-17 05:50:37 INFO cluster:1469 Executing action create on SVMs
2014-04-17 05:50:37 INFO cluster:593 Discovered node:
rackable_unit_serial: 10-64-20-110
node_position: A
node_uuid: ed763914-2c16-4aff-9b6b-d4ea962af9fe

2014-04-17 05:50:37 INFO cluster:632 Configuring Zeus mapping ({u'': 1}) on SVM node
2014-04-17 05:50:37 INFO cluster:650 Creating cluster with SVMs:
2014-04-17 05:50:37 INFO cluster:654 Disable fault tolerance for 1-node cluster
2014-04-17 05:50:39 INFO cluster:687 Waiting for services to start
Waiting on (Up, ZeusLeader) to start: ConnectionSplicer Medusa DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on (Up, ZeusLeader) to start: ConnectionSplicer Medusa DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on (Up, ZeusLeader) to start: DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on (Up, ZeusLeader) to start: DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on (Up, ZeusLeader) to start: AlertManager Arithmos SysStatCollector
Waiting on (Up, ZeusLeader) to start:
The state of the cluster: start
Lockdown mode: Enabled

CVM: Up, ZeusLeader
Zeus UP [14429, 14442, 14443, 14447, 14453, 14466]
Scavenger UP [14660, 14675, 14676, 14793]
ConnectionSplicer UP [14690, 14703]
Medusa UP [14760, 14775, 14776, 14780, 14940]
DynamicRingChanger UP [15946, 15973, 15974, 15986]
Pithos UP [15950, 15980, 15981, 15994]
Prism UP [15969, 15995, 15996, 16004]
AlertManager UP [16019, 16049, 16051, 16079, 16102]
Arithmos UP [16029, 16080, 16081, 16099]
SysStatCollector UP [16041, 16092, 16093, 16178]
2014-04-17 05:51:07 INFO cluster:1531 Success!

And voila! You can now log on to your instance of Prism Central!

Prism Central

Prism Central

As you can see, it looks quite the same as the regular 4.0 version, except that if you click on the top left “Prism Central” text, a menu will fold out on the left hand side. But, since we want to monitor a cluster, let’s go ahead and register a cluster.

To do so, just connect to your NOS 4.0 cluster, and click on the small gear symbol on the top right corner, and select “Prism Central Registration”. There, fill out the Prism Central IP, the username and password for Prism Central, and click on “Save”

Prism Central - Registration

Prism Central – Registration

If all goes well, the cluster registers, and you will see an event in your Prism Central stating that a user has been added (we support single sign on in Prism Central), and that a cluster has been added to Multicluster. And, you should now be able to see the new cluster that was registered in Prism Central:

Prism Central - Cluster registered

Prism Central – Cluster registered

To now manage that cluster, simply click on Prism Central on the top left, and then select the cluster from the list on the left hand side:

Prism Central - Cluster selection

Prism Central – Cluster selection

From there on, you can manage the cluster just like you would in your regular interface. My colleague Suda Srinivasan was kind enough to create a video that walks you through the interface:

So, that’s it for now. If you have any questions, feel free to let me know.

Installing VMs under KVM on Nutanix

27 02 2014

I’m getting more and more customer requests that are looking at alternatives for VMware, and are considering a different hypervisor. Since I’m more of a VMware guy, but I am always willing to learn new stuff, I figured I might as well share some info on how to set up the Nutanix cluster on KVM, and create an initial virtual machine.

I’m assuming you have at least some Linux knowledge, and that you were able to get the hosts and the controller VMs configured with an IP address. After that, the basic setup is pretty much the same. Visit the cluser_init page using the IPv6 link local address, which is in the format:


Which looks something like this:

Nutanix - Cluster Init

Nutanix – Cluster init

Fill out the information in that window, and click the “Create” button. Once that is done, you will see some messages popping up underneath:
Configuring IP addresses on node 13SM15400003/A...
Configuring IP addresses on node 13SM15400003/B...
Configuring IP addresses on node 13SM15400003/C...
Configuring the Hypervisor DNS settings on node 13SM15400003/A...
Configuring the Hypervisor DNS settings on node 13SM15400003/B...
Configuring the Hypervisor DNS settings on node 13SM15400003/C...
Configuring the Hypervisor NTP settings on node 13SM15400003/A...
Configuring the Hypervisor NTP settings on node 13SM15400003/B...
Configuring the Hypervisor NTP settings on node 13SM15400003/C...
Configuring Zeus on node 13SM15400003/A...
Configuring Zeus on node 13SM15400003/B...
Configuring Zeus on node 13SM15400003/C...
Initializing cluster...
not ready, trying again in 5 seconds...
Initializing cluster...
Cluster successfully initialized!
Initializing the CVM DNS and NTP servers...
Successfully updated the CVM NTP and DNS server list

What we are doing, is actually configuring the cluster with all the IP addresses, writing the cluster configuration to the underlying services, and starting the cluster for you. Give it a couple of minutes (usually 2 or 3 minutes will suffice), and you can now log on to the IP address of a controller VM, or the “Cluster External IP” that you put in, using the default username and password:

Nutanix - Cluster logon

Nutanix – Cluster logon

By the way, I disabled the background video by simply adding “?novideo=true” to the logon URL. This disables the video, and makes logon a bit faster, especially when working via a link that might not have the bandwidth that you would prefer.

I then created a storage pool by the name of “default”, and created a container with the same name. Once that is done, your cluster is ready for its first VMs.

Nutanix - Cluster ready

Nutanix – Cluster ready

Now, Nutanix relies on the management tools that a Hypervisor offers. In the case of vSphere, this would be vCenter. With KVM, or in our case KVM on CentOS, the selection is a bit more limited. Especially, since we make use of the Open Virtual Switch. That means, right now, we use libvirt as the management API, and wrote some extensions of our own. After all, your VMs will be located on storage that is being provided by Nutanix, so it would be good if we gave you some commands to make use of that storage, right? 😉

If we want to start the installation of a VM, we are first going to need an installation medium that we can use. So, I’m going to whitelist the default container I just created, and copy over a Ubuntu iso image:

Nutanix - Filesystem whitelist

Nutanix – Filesystem whitelist

Since you want to be able to see what was uploaded to the container, you can check from any of the controller VMs what is on there:
nutanix@NTNX-13SM15400003-A-CVM:$ nfs_ls

Now, just pick the host that you want to use for your VM, and create the VM using the virt_install command. For example:
virt_install --name bas_ubuntu_test --disk 32 --cdrom /default/ubuntu-13.04-server-amd64.iso --nic VM-Network --vcpus 2 --ram 4096

Which would result in the following:
nutanix@NTNX-13SM15400003-A-CVM:$ virt_install --name bas_ubuntu_test --disk 32 --cdrom /default/ubuntu-13.04-server-amd64.iso --nic VM-Network --vcpus 2 --ram 4096
2014-02-27 15:26:54 INFO Preparing nutanix disks: 0%
2014-02-27 15:26:57 INFO Preparing nutanix disks: 50%
2014-02-27 15:26:57 INFO Preparing nutanix disks: 100%
2014-02-27 15:26:57 INFO Creating libvirt storage pools: 0%
2014-02-27 15:26:59 INFO Creating libvirt storage pools: 50%
2014-02-27 15:26:59 INFO Creating libvirt storage pools: 100%
2014-02-27 15:26:59 INFO Running virt-install

Now you have multiple options. You could connect using virt-manager:

Nutanix - virt-manager

Nutanix – virt-manager

Or, alternatively, you could open up the VNC port that the VM is running on (or disable iptables alltogether), and use your favorite VNC client to manage the newly created VM:

Nutanix - VNC

Nutanix – VNC

Most of the commands that Nutanix implemented come with a syntax that is very similar to the native libvirt syntax, but the commands will be named with an underscore instead of a dash. For example live migration of a VM can be performed using:
virt_migrate --vm bas_ubuntu_test --destination --live

That’s it for a rough overview. If you have any questions, feel free to contact your local SE, or leave a note in the comments. 🙂

Nutanix – What do you mean: “You are not a storage company”…?

9 08 2013

Image copyright of the Davis Museum

Image copyright of the Davis Museum

“You are a black guy, you must be great at dancing and basketball”. “You’re a blonde? Let me explain that joke to you once more”.

Stereotypes. We all know them, we all apply them in some form or the other. We put things in boxes after a quick look, and every drawer has a different label and content to separate the stereotypes. But what if it doesn’t work that way?

Since I joined Nutanix, I’ve been in several customer and partner meetings. Some of the people I’ve get got the idea right away. We are doing something new. Others put us in to a respective box or drawer. “You are a storage company” is one of the classic pieces of feedback. Or, “So you do virtual desktop infrastructure?”.

But there’s more to it. We offer a combination of commodity hardware, combined with a piece of software, and sell that as a solution. And while the use case of virtual desktops is a great one, we can also run things like Splunk, Hadoop and classic server virtualization workloads.

And while we combine the benefits of a shared storage approach to run workloads, we’re not a storage company. We utilize features offered by shared storage to make your life easier. Each node performs its operations on the local storage, but I can use the “Nutanix Distributed File System” or NDFS to create an abstracted layer that offers many of the shared storage benefits. An example would be a shared container for my virtual machines, that are accessible to all of the hosts, enabling features like live migration between hosts.

While that works out really well with our customers, and it gives you the idea you have a SAN or NAS underneath the hoods, Nutanix’s main point is not to replace your SAN or NAS. We want to offer you a “Virtual Computing Platform”, a way to make your life easier when installing, configuring and deploying virtualized workloads and solutions.

That works great, and we’ve received great feedback. There seems to be a slight disconnect though. That begins when people start asking questions like:

What do you mean: “You are not a storage company”…?

A fair question by all means, but the simple answer is: No, we are not.

A simple example that seems to come up as of late is the following. How do I share disk space from your file system directly in to a virtual machine? While there is a way to export the storage directly in to a VM (for example via NFS), this bypasses some of the concepts we utilize. By default, we mount a datastore using an NFS IP address of, which runs over a virtual switch that has no uplinks. Since we are talking about traffic that stays within the same vSwitch, we can work at blazing speeds that are not limited by the speed of the physical NIC.

If I were to mount the NFS share from a virtual machine (or a different host), we could use the external IP of the Controller VM. The problem here, is that since the external IPs are different between controller VMs, if you were to migrate your NFS client VM to a different host, everything would go over the regular network. Also, if the controller VM that you connect to as an NFS Server would be offline, your NFS share is not accessible.

The thing is, the Nutanix block is designed to work this way. It offers great flexibility when it comes to running virtualized workloads, but it is not a 100% distributed storage system. We didn’t intend on being a storage system.

It then boils down to design. Is there a way around this? Certainly.

If you want to create a distributed CIFS file share, take a look at solutions like DFS from Microsoft. You can run multiple VMs inside of a container/datastore, and just pass the disk space of the VM through. If you need more space, just add more VMs on a different node, and add capacity, and off you go. And if you run out of space on your cluster? Just add another Nutanix node, get a VM up and running, and follow the same procedure.

That way, you are actually utilizing the distributed nature of our virtual compute platform, and running your storage services in a distributed manner. Gluster FS could be a possible solution to achieve the same thing with NFS on Linux.

And like I said, if this sounds like we are not a storage company? You are absolutely right, we are not. So you might want to categorize us under a different label, put us in a different box, or create an entirely new stereotype. 😉

Upgrading your Nutanix NX-2400 block from ESXi 5.0 to ESXi 5.1 using a USB thumb drive.

16 07 2013

At the moment, I’m lucky enough to have a Nutanix block at home that I use for demos (it’s coming along to Switzerland with me tomorrow). It’s not the model with the highest specs, but it helps in giving customers a chance to actually see the kit, and give partners some hands-on time. In case you are wondering, I’m actually working with a NX-2400, or a 4-node NX-2000 cluster, hence 2400.

Thing is though, that it was running an older version of the Nutanix Operating System (NOS), which I upgraded to the latest version (NOS 3.1) without a hitch, and it was running ESXi 5.0. And to play with some of the latest features, I actually decided to upgrade to ESXi 5.1, and I figured I might as well share how that worked out for me.

The steps are relatively simple, but I figured I’ll document them here anyway. One word of caution though:

    This was done with the latest info from the Nutanix knowledge base. Be sure to check if there are updated instructions available prior to upgrading your own block.

So, step one is to actually get the installation media for ESXi 5.1. In case of the NX-3000, you can use the standard ESXi 5.1 image. For the NX-2000 systems, you need to use an image that is customized by Nutanix. Contact myself or your local systems engineer to get the download location.

Next, create a bootable USB stick using the image. Easiest way I found is to actually format the stick with FAT32 as the filesystem. I recommend using a Windows system, or a Windows VM, since no matter what I tried, I couldn’t get it to boot using a Mac. Once the drive is formatted, I used UNetbootin:

UNetbootin ESXi 5.1 Nutanix

Click on “Disc Image” and select the ISO file. Make sure “USB Drive” is selected, and point it to the correct drive. Then click on “OK”, and watch it go to work. If it gives you a message stating that menu.c32 is already present, click on the “Yes” button.

We’ll also need to edit the NFS heartbeat timeout settings. To do that, log on to vCenter, select the node and go to “Software” -> “Advanced settings”. There go to the NFS entries, and modify the “NFS.HeartbeatTimeout” setting to 30 seconds. Do that for each host.

Next, we need to make sure the multiextent module is loaded. Add the following lines to /etc/rc.local.d/ on each host (if not already there):
#added to support multiextent
localcli system module load -m multiextent
#end of adding

Then restart the host.

Once you are done, it is time to start the upgrade. Go in to the BIOS (using the Delete key) on the node you want to upgrade, and change the boot order so that you actually start off of your USB stick. Once you save the config and restart, you will be given a menu where you select the second option:

Unetbootin - Nutanix ESXi 5.1 upgrade menu

After that you should be able to see the trusted ESXi boot sequence:
ESXi 5.1 boot screen

At the installation screen, just hit the “Enter” key to continue with the installation. Read the license agreement, and continue with F11. Next, you are asked where the installation should reside. Normally you should see the Intel SSD already have a VMFS partition, indicated by the small asterisk in front of the disk. Select that disk and press “Enter” to continue:
ESXi 5.1 upgrade VMFS

Next, a prompt should show up asking if you want to upgrade. Select that option, and press “enter” once more:
Upgrade VMFS ESXi 5.1

The final step is to confirm your upgrade by pressing the “F11” key. Once the upgrade is done, remove the USB thumb drive, and reboot the server by again hitting the “Enter” key. Let the node reboot, change the boot order to the original sequence, and, tadaaaaaa:
Nutanix - ESXi 5.1 upgrade complete

Now, obviously this would be easier using the vSphere Update Manager, but this was the solution I used, since I only installed the vCenter virtual appliance. Not pretty but it works.

One key thing left to do, is to re-register the controller VMs on your ESXi host. You can do this via the vSphere client going directly to the ESXi host. Just right-click the VM and select “remove from inventory”. Then browse the datastore, go to the folder saying “ServiceVM-1.24_Ubuntu” and add the VM to the inventory using the VMX file. You can now start your VM after you confirmed that you moved it. 🙂

The other alternative to re-register your VM using vim-cmd via an SSH session on to your ESXi host. Just check which VMs you have running:
vim-cmd vmsvc/getallvms

Vmid Name File Guest OS Version Annotation
190 NTNX-TRAIN2-S11317022510746-A-CVM--2- [NTNX-local-ds-S11317022510746-A] ServiceVM/ServiceVM.vmx ubuntu64Guest vmx-07
Remember the VMID and de-register the VM:
vim-cmd vmsvc/unregister [vmid of controller VM]Now simply re-register the VM:
vim-cmd solo/register [/full/file/path/to/the/controller_vm_name.vmx]You might want to rename the controller VM once you have registered it.

Should you have any issues starting the VM, make sure that there is no line saying:
sched.mem.prealloc = "TRUE"in the .vmx file of you VM. If this line is present, remove it, and re-register your VM.

Nutanix – 2013 vExpert gift

5 06 2013

nutanix-logo-transparent-hirez300So, this is something I found out just after my first day at Nutanix. There is a Facebook post by Nutanix, stating the following:

Nutanix would like to congratulate all #vExpert winners with a personalized pint glass at #VMWorld! Winners- reach out to us if interested.

I sent out a tweet, and got back a couple of replies. Some folks don’t use Facebook, some won’t be visiting VMworld in the US (or Europe for that matter), and it wasn’t quite clear what info was needed.

In an effort to consolidate this a bit more, I set up a Google spreadsheet, that just has some basic info. Your first name, last name, Twitter handle, and if you will be visiting VMworld in the US or Europe. You don’t have to sign in, editing is possible when accessing the document using the direct link.

Should you not visit, I think we can arrange that the personalized pint glass will be shipped to you, and we will follow up with you regarding details on shipping. Just make sure that you either follow the Nutanix Twitter account, or my Twitter account so that we can send you a direct message should we need your shipping information.

The link to the document is:

And in case you are wondering, I took the liberty of filling out the info of the people who had already replied to me via Twitter. And yes, we will be checking if you are on the official list. 😉

Time for a change: Keep calm and…

15 05 2013

Keep calm and join Nutanix.

Keep calm and join Nutanix - Picture by Christian Mohn

Keep calm and join Nutanix – Picture by Christian Mohn

Yep, no sense in beating around the bush. I resigned with EMC, and after wrapping up open topics, I will be starting as the first German systems engineer for Nutanix on June 17th.

I’ve learned incredibly much at EMC. After joining EMC in 2010, I was lucky to be part of a team that has done some incredible things. I feel like the vSpecialist team set a bar on how customer interaction can work, how a team of great individuals can combine in to something much more, and transform the way a company goes about. I learned ways to present information (hopefully in an interesting way), made friends, was able to help customers, worked on several certifications, and always had the feeling that I was still the dumbest guy on the team. I loved the fact that I was able to still ask tough questions internally, without being viewed as “that guy that just sits around nagging”. I’ve got so much to be grateful for, and I am. People like Chad Sakac or Wade O’Harrow who saw some potential in me, or someone like Holger Daube who has been a better boss to me than I could wish for. There are too many to name and thank individually, but thank you to all of you!

But I am moving on. After talking to several people, and discussing, reading things like this, I can’t help but feel that this is a great chance. I can try to set up something new, help define solutions, and get to see what it looks like working in a smaller company, with what I’m expecting to be an even crazier pace.

So, here’s to seeing you on the flip-side, and having fun with something new! 🙂

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