Kubernetes, Nutanix, Virtualization

[Shorts] Connecting to Nutanix Karbon using Windows

Nutanix has released a product called “Karbon” which according to the website allows you to:

Get a production-ready Kubernetes Cluster up and running in 20 minutes.

Now, I’ll leave it up to the marketing people to verify if it takes 20 minutes or not. But once you have your cluster up and running, our developers assumed that anyone connecting to the Karbon cluster will use a Linux based operating system.

Since that isn’t the case for everyone, and I like to try other things, I wanted to see if I can connect to the Karbon cluster using Microsoft Windows as the operating system. This works fine, but there will be a couple of things you need to do.

First, log on to your Karbon cluster, select the cluster that you want to connect to, and from the “actions” menu at the top select the “SSH Access option”, which will give you a dialog window with a download link:

Screenshot 2019-08-07 at 15.19.08

Download the file in a location of your choice. Next, open the file, but open it in an editor that is capable of properly handling files created on Linux. This is important since there is a difference in the way a press of the “Enter” key is written in text files between the operating systems.

Once the file is opened, you will see two larger blocks of information. One part can be found in the “private_key” part of the file, and one in the “user_cert” part of the file. First off, select all of the lines after:

private_key='

So essentially you are copying everything from (and including):

-----BEGIN RSA PRIVATE KEY-----

down to (and including):

-----BEGIN RSA PRIVATE KEY-----

But make sure you do not include the single quote at the start and the end. Take this and save it as a new file, for example called “karbon-user”

Then, do the same thing for everything following:

user_cert='

And copy everything starting with “ssh-rsa-cert-v01” down to the last character of that long string, but do not include the final single quote. Save that as a file for example called  “karbon-user-cert.pub”

Next up, start PowerShell on your Windows system as an administrator and start the ssh-agent service:

Start-Service ssh-agent

And if you want to have it start automatically:

Set-Service ssh-agent -StartupType Automatic

Then add your users private key file that you save before:

ssh-add C:\Users\Bas\Downloads\karbon-user

Obviously replace the path above to the location on your system 😉

Next, the only thing you have to do is ssh into the IP address of your Karbon VM while passing the public key we also saved before:

ssh -i C:\Users\Bas\Downloads\karbon-user-cert.pub nutanix@192.168.0.5

Again, replace the path to the file, and replace the IP to your VMs IP. But once that is going, you can connect to your Karbon VMs and work with them without having to set up a Linux system. 🙂

Screenshot 2019-08-07 at 15.39.54

Nutanix, Performance, SAP, Uncategorized

RDMA on Nutanix AHV and the discomfort of heterogeneous environments

In the process of setting up our new environment for SAP HANA validation work, I spent some time in the data center setting up our environment, and I ran into some caveats which I figured I would share.

To set the stage, I am working with a Lenovo HX Nutanix cluster. The cluster consists of two HX-7820 appliances with 4x Intel 8180M CPU’s, 3TB RAM, NVMe, SSD and among other things two Mellanox CX-4 dual port NICs. The other two appliances are two HX-7821 with pretty much the same configuration except these systems have 6TB of RAM. The idea is to give this cluster as much performance as we can and to do that we decided to switch on Remote Direct Memory Access, also called RDMA in short.

Now, switching on RDMA isn’t that hard. Nutanix has added support for RDMA with AOS version 5.5, and according to our “one-click” mantra, it is as simple as going into our Prism web interface, clicking the gear symbol, going to “Network Configuration” and from the “Internal Interface” tab enable RDMA and put in the info about the subnet and VLAN you want to use as well as the priority number. On the switch side, you don’t need anything extremely complicated. On our Mellanox switch we did the following (note that you’d normally need to disable flow control on each port, but this is the default on Mellanox switches):

interface vlan 4000
dcb priority-flow-control enable force
dcb priority-flow-control priority 3 enable
interface ethernet 1/29/1 dcb priority-flow-control mode on force
interface ethernet 1/29/2 dcb priority-flow-control mode on force
interface ethernet 1/29/3 dcb priority-flow-control mode on force
interface ethernet 1/29/4 dcb priority-flow-control mode on force

With all of that in place, you would normally expect to see a small progress bar and that is it. RDMA set up and working.

Except that it wasn’t quite as easy in our scenario…

You see, one of the current caveats is that when you image a Nutanix host with AHV, we pass through the entire PCI device, in this case the NIC, to the controller VM (cVM). The benefit is that the cVM now has exclusive access to the PCI device. The issue that arises is that we currently do not forward a single port, which isn’t ideal in the case of a NIC that has multiple ports. Add on top of that the fact that we don’t give you the choice which port to use for RDMA, and the situation becomes slightly muddied.

So, first off. We essentially do nothing more than see if we have an RDMA capable NIC, and we pass through the first one that find during the imaging process. In a normal situation, this will always the RDMA capable NIC on the PCI-slot with the lowest slot number. It will also normally be the first NIC port that we find. Meaning that if you have for example a non-RDMA capable Intel NIC in PCI slot 4, and two dual port RDMA capable cards in slot 5 and 6, your designated RDMA interface is going to be the first port on the interface in slot 5.

Since you might want to see what MAC-address is being used, you can check from the cVM by running the ifconfig command against the rdma0 interface. Note that this interface by default will exist, but isn’t online, so it will not show up if you just run an ifconfig command without parameters:

ifconfig rdma0
rdma0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::ee0d:9aff:fed9:1322  prefixlen 64  scopeid 0x20
        ether ec:0d:9a:d9:13:22  txqueuelen 1000  (Ethernet)
        RX packets 71951  bytes 6204115 (5.9 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 477  bytes 79033 (77.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

To double check if you have the correct interface connected to your switch ports my tip would be to access the lights out management interface (IMM / ILO/ iDRAC, IPMI, etc.) and check your PCI devices from there. Usually these will tell you the MAC of the interface for the various PCI devices. Make sure you double check if you are connected to the right physical NIC and switch port.

The next topic that might come up is the fact that we will automatically disable c-states on the AHV host in the process of enabling RDMA. This is all done in the background, and again normally will be done automatically. In our case, since we added a couple of new nodes to the cluster, the BIOS settings were not the same across the cluster. The result of that was that on the AHV hosts, the HX-7820 nodes had the following file available that contained a value of “1”:

/sys/devices/system/cpu/cpu*/cpuidle/state[3-4]/disable

Due to the BIOS settings that were different on the NX-7821 hosts that we added, this file and the cpuidle (sub-)directories didn’t exist on the host. While the RDMA script tried to disable c-states 3 and 4 on the hosts, this was only successful on two out of the four nodes in the cluster. Upon comparing the BIOS settings we noticed some deviations in available settings due to differences in versions, and differences in some of the settings as they were delivered to us (MWAIT for example). After modifying the settings to match the other systems, the directories were now available and we could apply the c-states to all systems.

While we obviously have some work to do to add some more resiliency and flexibility to the way we enable RDMA, and it doesn’t hurt to have an operational procedure to ensure settings are the same on all systems before going online with them, I just want to emphasize one thing:

One click on the Nutanix platform works beautifully when all systems are the same.

There are however quite a couple of caveats that come into play when you work with a heterogeneous environment/setup:

  • Double check your settings at the BIOS level. Make them uniform as much as you can, but be aware of the fact that sometimes certain settings or options might not even be available or configurable anymore.
  • Plan your physical layout. Try not to mix a different number of adapters per host.
  • Create a physical design that can assist the people cabling with what to plug where to ensure consistency.
  • You can’t always avoid making changes to a production system, but if at all possible, have a similar smaller cluster for the purpose of quality assurance.
  • If you are working in a setup with a variety of systems things will hopefully work as designed but might not. Log tickets where possible, and provide info that goes a bit further than “it doesn’t work”. 😉

Oh, and one more thing. Plan extra time. The “quick” change of cables and enabling of RDMA ended up in spending 4 hours in the data center working through all of this. And that is with myself being pretty familiar with all of this. If you are new to this, again if at all possible, take your time to work through this, versus doing this on the fly and running into issues when you are supposed to be going live. 🙂

Nutanix, Nutanix AHV, SAP, Virtualization

Bas, what the hell have you been doing? – an​ SAP HANA on Nutanix story

To say my last blog post is “a while ago” would a grave understatement. Unfortunately, I’ve mainly been busy with something that was entirely new for Nutanix, and with the amount of work involved and the sensitive nature of what I was working on, there was relatively little room left to blog. Especially since I usually ended up blogging about stuff, I stumbled upon while doing my job or researching.

This all started with me changing from my presales focussed role to our internal “Solutions & Performance Engineering” team, which focusses on the business-critical applications running on the Nutanix platform. In essence, those applications that are the lifeblood of a company. Applications which, if they are unavailable, will cost the company significant amounts of money.

One of those applications is SAP, or more specifically the SAP HANA in-memory database. My colleagues (mainly Kasim Hansia, Rainer Wacker and Alexander Thoma) had already been doing a great job, and all of the SAP applications were certified to run on the Nutanix platform in November 2016. The big question was always “When can we run SAP HANA on Nutanix?”.

Working on the answer to this question is what I’ve been busy with the last year or so. While I won’t bother you with the specific details on the business side of things, I do want to take a bit of time to show what it’s like to go through the process of validating a new application.

First off, the SAP HANA in-memory database is an application that scales to levels that many people won’t ever see in action. You can run HANA in two ways. You either scale up the resources of a single server, for example running with up to 20TB of memory, or you can scale out by adding multiple servers and distributing the load across all servers.

Now, SAP has given the customer two options to select hardware to run SAP HANA. One is an “appliance model” where you choose a configuration as a whole, and everything will run in a pre-tested and validated fashion. You are ensured of a specific behavior of the whole system while running your application. The other option is something called “Tailored Data Center Integration” or TDI in short, where in essence you select your hardware from a hardware compatibility list and have the freedom to mix and match.

What we have done is work with SAP to introduce a new third category called “Hyperconverged Infrastructure” or HCI. The HCI category assumes that we are running SAP HANA in a virtualized fashion, and “collapse” several infrastructure components such as compute and storage to an integrated system.

The limitations on the maximum sizes for this category are smaller than for the other two categories, but the requirements that are in place for this certification do not offer much more leeway. For example, a storage test to ensure storage performance, where initially log overwrite operations needed to have latency <= 400 microseconds (this changed later on). Another example is a test suite of close to 700 tests that emulate real-world issues, and the performance delta is then compared to a bare-metal installation, with only a specific maximum performance delta between the two giving you a passing grade.

All this meant that I had my work cut out for me from the start. We started off working with a server model that wasn’t qualified before, before switching to the validation hardware, namely a Lenovo SR950. A big four-socket server with the fastest CPUs we could use, namely the Intel Xeon Platinum 8180M Processors, 3072 GB of RAM, 3.84TB SSDs and 1.6 TB NVMes.

Now, as much as Nutanix is a software company, we do strictly check that hardware meets specific prerequisites to ensure a smooth user experience and to make sure that certain performance metrics are a given. The issue is that all of the checks and functionality in place didn’t work for this new hardware. Simple things like making the status indicator LED for the NVMe light up, or mapping the physical drive locations back to the diagram view in Prism. It meant modifying Python files that handle how hardware is accessed, packaging everything back up into Python egg files, restarting services and then magically seeing drives that the system was able to access. Or passing through NICs so that we could test with “RDMA over Converged Ethernet” or RoCE, and changing BIOS settings to ensure maximum performance.

And while pushing the underlying hardware to its limits, it also meant we had to dive deep, and I mean very deep, into the software side of things. From things like experimenting with c-states on the CPU and NIC multiqueueing in the virtual machines, down to changing parameters in our product, ensuring that specific CPU features are passed through, the pinning of virtual CPUs to their physical location or making changes to how often a vmexit instruction is called.

I can’t go into all of the specific details since some of it is Nutanix’ intellectual property, but I’ll check what I can share in future posts, and if you have any specific questions, please ask them, and I’ll try to answer as best I can. What I can say is that we pushed the limits of our platform and quite a couple of the things we found are going to be implemented back into the product, and I expect a lot of those changes to show up in the release notes of an upcoming release.

Fact is, I learned a ton of new things, and this all culminated in our validation for pre-production use of SAP HANA on Nutanix AHV as announced in https://www.nutanix.com/2018/06/05/finally-can-talk-sap-hana-nutanix/, and we are working full steam ahead on the last steps to get production support. It was and continues to be one hell of a journey, and I just wanted to give you guys a bit of insight into what it is like working on the engineering side of the Nutanix platform, and what a project like this entails.

I want to finish with a special thank you to (in no particular order), Rainer, Alexander, Kasim, Malcolm, Jonathan, and the extended team. It’s been one heck of an experience! 🙂

Containers, Nutanix

Getting started with CoreOS on Nutanix Community Edition

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:

#cloud-config
ssh_authorized_keys:
  - ssh-rsa AAAAB3NzaC1...
coreos:
  etcd2:
    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
    listen-client-urls: http://0.0.0.0:2379,http://0.0.0.0:4001
    listen-peer-urls: http://0.0.0.0:2380
 units:
    - name: etcd2.service
    command: start
    - name: 00-eth0.network
    runtime: true
    content: |
      [Match]
      Name=eth0
      
      [Network]
      DNS=<your-dns-ip-here>
      Address=<etcd-vm-ip-here>/16
      Gateway=<your-gateway-ip-here>

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:

#cloud-config
ssh_authorized_keys:
 - ssh-rsa AAAAB3NzaC1...
coreos:
  etcd2:
    proxy: on
    initial-cluster: etcdserver=http://<etcd-vm-ip-here>:2380
    listen-client-urls: http://localhost:2379
  fleet:
    etcd_servers: http://localhost:2379
    metadata: "role=etcd"
  units:
    - 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... 192.168.96.248 role=etcd
8e974c05... 192.168.79.25  role=etcd
a899b944... 192.168.114.8  role=etcd
f916eb93... 192.168.3.179  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.../192.168.96.248

core@CoreOS-1 ~ $ fleetctl list-units
UNIT          MACHINE                    ACTIVE   SUB
hello.service 1c24fc23.../192.168.96.248 inactive dead
KVM, Nutanix, Storage, Uncategorized, Virtualization, VMware

Nutanix OS 4.0 – Prism Central

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):

8GB RAM
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:

DEVICE="eth0"
NM_CONTROLLED="no"
ONBOOT="yes"
BOOTPROTO="none"
IPADDR="10.64.20.110"
NETMASK="255.255.255.0"
GATEWAY="10.64.20.1"

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 10.64.20.110 create
2014-04-17 05:50:37 INFO cluster:1469 Executing action create on SVMs 10.64.20.110
2014-04-17 05:50:37 INFO cluster:593 Discovered node:
ip: 10.64.20.110
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'10.64.20.110': 1}) on SVM node 10.64.20.110
2014-04-17 05:50:37 INFO cluster:650 Creating cluster with SVMs: 10.64.20.110
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 10.64.20.110 (Up, ZeusLeader) to start: ConnectionSplicer Medusa DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on 10.64.20.110 (Up, ZeusLeader) to start: ConnectionSplicer Medusa DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on 10.64.20.110 (Up, ZeusLeader) to start: DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
...
...
...
Waiting on 10.64.20.110 (Up, ZeusLeader) to start: DynamicRingChanger Pithos Prism AlertManager Arithmos SysStatCollector
Waiting on 10.64.20.110 (Up, ZeusLeader) to start: AlertManager Arithmos SysStatCollector
Waiting on 10.64.20.110 (Up, ZeusLeader) to start:
The state of the cluster: start
Lockdown mode: Enabled

CVM: 10.64.20.110 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.

KVM, Nutanix, Storage, Virtualization

Installing VMs under KVM on Nutanix

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:

http://ntnx-%5Bblock_serial_number%5D-%5Bnode_position%5D-cvm.local:2100

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:10.0.0.30:~$ nfs_ls
ubuntu-13.04-server-amd64.iso

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:10.0.0.30:~$ 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 batch_worker.py:211 Preparing nutanix disks: 0%
2014-02-27 15:26:57 INFO batch_worker.py:211 Preparing nutanix disks: 50%
2014-02-27 15:26:57 INFO batch_worker.py:211 Preparing nutanix disks: 100%
2014-02-27 15:26:57 INFO batch_worker.py:211 Creating libvirt storage pools: 0%
2014-02-27 15:26:59 INFO batch_worker.py:211 Creating libvirt storage pools: 50%
2014-02-27 15:26:59 INFO batch_worker.py:211 Creating libvirt storage pools: 100%
2014-02-27 15:26:59 INFO kvm_domain_template.py:184 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 10.0.0.20 --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. 🙂

Clustering, GestaltIT, Nutanix, Storage, VMware, vSphere

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

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 192.168.5.1, 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. 😉