Tag Archives: ESXi

Hyper-converged infrastructure – Part 2 : Planning an Cisco HyperFlex deployment

I recently got the chance to deploy a Cisco HyperFlex solution that is composed of 3 Cisco HX nodes in my home lab. As a result, I wanted to share my experience with that new technology (for me). If you do not really know what all this “Hyperconverged Infrastructure hype” is all about, you can read an introduction here.

Cisco eased our job by releasing a pre installation spreadsheet and it is very important to read that document with great attention. It will allow you to prepare the baseline of your HC infrastructure. The installation is very straightforward once all the requirements are met. The HX infrastructure has an important peculiarity, it is very very very (did I say very) sensitive …. if one single requirement is not met, the installation will stall and you will be in a delicate situation because you could have to wipe the servers and restart the process. As a result, you could lose precious hours.

Cisco has a way to automate the deployment and to manage your HX cluster.Finally, The HX installer will interact with the Cisco UCSM, the vCenter, and the Cisco HX Servers.

It is especially relevant to note that the Cisco HX servers are tightly integrated with all the components described in the picture below:

HyperFlex Software versions.

As usual with this kind of deployment, you have to make sure that every version running in your environment is supported.  We will run the 2.1(1b) version in our lab and will upgrade to 2.5 at a later time. We need to make sure that our FI UCS Manager is running 3.1(2g).

In addition, the dedicated vCenter that we will use is running the release 6.0 U3 with Enterprise plus licenses.

Nodes requirements.

You cannot install less than 3 nodes in a Cisco HyperFlex Cluster. Because the HX solution is very sensitive, it is mandatory to have some consistency across the nodes regarding the following parameters:

  • VLAN IDs
  • Credentials 
  • SSH must be enabled
  • DNS and NTP
  • VMware vSphere installed.

Network requirements.

First of all, the HyperFlex solutions require several subnets to manage and operate the cluster.

We will segment these different types of traffic using 4 vlans:

  • Management Traffic subnet: This dedicated subnet will be used in order for the vCenter to contact the ESXi server. It will also be used to manage the storage cluster.
    • VLAN 210: 10.22.210.0/24
  • Data Traffic subnet: This subnet is used to transport the storage data and HX Data Platform replication
    • VLAN 212: 10.22.212.0/24
  • vMotion Network: Explicit
    • VLAN 213: 10.22.213.0/24
  • VM Network: Explicit
    • VLAN 211: 10.22.211.0/24

Here is how we will assign IP addresses to our cluster:

UCSM Requirements.

We also need to assign IP addresses for the UCS Manager Fabric Interconnect that will be connected to our Nexus 5548:

  • Cluster IP Address: 
    • 10.22.210.9
  • FI-A IP Address:
    • 10.22.210.10
  • FI-B IP Address:
    • 10.22.210.11
  • A pool of IP for KVM:
    • 10.22.210.15-20
  • MAC Pool Prefix:
    • 00:25:B5:A0

 

DNS Requirements.

It is a best practice to use DNS entries in your network to manage your ESXi servers. Here we will use 1 DNS A records per nodes to manage the ESXi server. The vCenter, Fabric Interconnect and HX Installer will also have one.

The list below will show all the DNS entries I have used for this lab:

  • srv-hx-fi
    • 10.22.210.9
  • srv-hx-fi-a
    • 10.22.210.10
  • srv-hx-fi-b
    • 10.22.210.11
  • srv-hx-esxi-01
    • 10.22.210.30
  • srv-hx-esxi-02
    • 10.22.210.31
  • srv-hx-esxi-03
    • 10.22.210.32
  • srv-hx-installer
    • 10.22.210.211
  • srv-hx-vc
    • 10.22.210.210

This sounds very basics and as a consequence, it is CRITICAL that these steps are performed PRIOR any deployment otherwise you will waste a lot of time trying to recover (at some point you would have to wipe your servers and reinstall a custom ESXi image on each one). 

Finally, In the next blog post, I will show how to install the vCenter, The Fabric Interconnect and the HX installer needed for the HyperFlex deployment.

In conclusion, do not hesitate to leave a comment to let me know if you encountered any issue while planning your deployment.

Thanks for reading!  

Cisco Expressway Setup

I am currently working on a Cisco Jabber project and my customer main requirement is that every users must be able to place calls in an easy way regardless from their location. Since the BYOD and Mobility are the trends I recommended the Cisco Expressway product line. I won’t go deep on how the expressway is working (this will be part of another blog post/series) but I’d rather share my experience regarding how to install an expressway. First and foremost I would like to say that I  have deployed 2 expressways for other customers and for my own lab and that I had no issue so far :). The problem here is specific to a particular ESXi version. I don’t have vCenter in this environment so the procedure slightly differs and I would heavily recommend to use the following documentation: Cisco Expressway VM deployment guide (8.2) When it comes to finalize the deployment I had this error :

OVA_Error
  After a quick lookup I found many issues like that on the internet (always feel good when you are not alone right ? 🙂 ) VMware OVF Deployment KB They basically say that there is maybe an issue with the cert file when it is a multiple of 1024 and it is !!

  The workaround would be to deploy the .ova with the Open Virtualization Format Tool What I did is the following, I used that tool to recreate the OVA template from Cisco.

Let’s check both OVA files to see what it changes:

OVA_Change
 

The certificate is gone from the template and you can see that ESXi can not verify the publisher

OVA_New
 

As opposed to the original OVA Template

OVA
 

The ESXi is running 4.1 and this issue has not happened on version 5.1 … I guess it was time to upgrade anyway 🙂 

My customer wanted me to open a TAC case to confirm that we could go live using that “hack” and Cisco told us that they are ok with that, obviously.

 

Nicolas