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Month: December 2016

VMware PowerCLI – Introduction

VMware PowerCLI – Introduction

To begin the jurney with PowerCLI we need to start from the installation of PowerCLI itself.

The installation can be done on a Windows based system, that could be some kind of an administration server. The installation files can be found on this VMware site.

There are a few versions available, they are released asynchronously with vSphere and the version numbers do not exactly correspond to vSphere versions. The most recent version is 6.5 whilst there are other like 6.3, 6.0 or 5.8 available.

Before you install the PowerCLI I recommend to change the Execution Policy of Powershell. It is required to run scripts. To do it, run Windows PowerShell as administrator and execute fallowing command:

Set-ExecutionPolicy RemoteSigned

The installation process is really straightforward, that’s why I will not spam the screanshoots of installations here.

After you finish the installation you can run it and see the first Welcome screen like this:

powercli1

 

The first command I suggest to use is:

Get-VICommand

it lists all the available commands. However to display any information about virtual infrastructure you need to connect to a vCenter server or ESXi host. We will do it in the next part after introduction of useful tools which can be used in conjunction with PowerCLI.

vSphere 6.5 – What’s new in networking  

vSphere 6.5 – What’s new in networking  

 

In this article I will try to review all new network features.

1. vmknic gateway

  • Each VMKERNEL port can have its own Gateway.
  • This will make it easy for vSphere features to function seamlessly.
  • This eliminates the need for adding and maintaining static routes.

network1

Before vSphere 6.5 there was only one default gateway allowed for all VMKernel ports in an ESXi host. vSphere features such as DRS , iSCSI, vMotion, etc. leverage  that use VMKERNEL ports are constrained by this limitation. Many of the VMKERNEL ports were not routable without the use of static routes unless they belonged to a subnet other than the one with the default gateway. These static routes had to be manually created and were hard to maintain.

vSphere 6.5 provides the capability to have separate  default Gateways for every VMKernel port. This simplifies management of VMKernel ports and eliminates the need for static routes.

Prior to vSphere 6.5, VMware services like DRS, iSCSI, vMotion & provisioning leverage a single gateway. This has been an impediment as one needed to  add static routes on all hosts to get around the problem. Managing these routes could be cumbersome process and not scalable.

vSphere 6.5 provides capabilities, where different services use different default gateways. It will make it easy for end users to consume these feature without the need to add static routes. vSphere 6.5 completely eliminates the need for static routes for all VMKernel based services making it simpler and more scalable.

 

2.SR-IOV provisioning:

VM provisioning workflow prior to vSphere 6.5, for SR-IOV devices required the user to manually assign the SR-IOV NIC.  This resulted in VM provisioning operations being inflexible and not amenable to automation at scale. In vSphere 6.5 SR-IOV devices can be added to virtual machines like any other device making it easier to manage and automate.

 

3.Support for ERSPAN:

ERSPAN mirrors traffic on one or more “source” ports and delivers the mirrored traffic to one or more “destination” ports on another switch. vSphere 6.5 includes support for the ERSPAN protocol.

network2

 

4.Improvements in DATAPATH:

 vSphere 6.5 has data path improvements to handle heavy load. In order to process large numbers of packets, CPU needs to be performing optimally, in 6.5 ESXi hosts leverage CPU resources in order to maximize the packet rate of VMs.

network3

Where are the improvements being made ?

  1. VMXNET 3 optimization
    1. Using copy TX for small messages size (<=256B)
    2. Optimized usage of pinned memory
  2. Physical NIC improvements
    1. Native driver support for Intel cards (removes overhead of translating from VMkernel to VMKLinux data structures)
  3. CPU Scheduling Improvements
    1. Up to 8 separate threads can be created per vNIC
      • To enable on VM level add:

ethernetX.ctxPerDev = “3” to vmx file

 

Summary:

  • Optimizing code to improve efficiency
  • Allowing the ability to increase thread count for networking
  • Introducing support for more native drivers (Intel)
  • VMXNET3 enhancements

 

VCAP6-DCV Exam Experience

VCAP6-DCV Exam Experience

There are a few such articles on the Internet. I think, read them all some weeks ago while preparing to my own exam.

However, I’d like to share with you my own observations.

 

Let’s start from the begining -how did I prepare for the exam?

Well, behind the real experience and VCP5/6 done already I went through the VMware blueprint for the exam. Almost every objective was tested in the lab, even it was quite obvious I wanted to review it, especially using Web Client. (yes, unfortunatelly I still prefer the C# client).

There are two helpful study guides written on these blogs:

Thank you guys!

I’ve also went through the Hands on Labs which Kyle recommends:

  • HOL-SDC-1602 – vDS, Content Libraries, Auto Deploy, Host Profiles
  • HOL-SDC-1627 – VSAN, vVOLS, Storage Policies
  • HOL-SDC-1604 – Performance
  • HOL-SDC-1607 – PowerCLI

There are newer verions of these however they are still awailable in the archive.

 

The next step – day of the exam.

I wasn’t able to take a day off so the exam was started afternoon. If you have a possibility to take day off and allocate it just for the exam I’d recommend doing so. The exam takes 190 minutes + 15 minutes for reading instruction, etc. It’s worth to read it carefully expecially about navigation and possibilities how to copy data inside the VMs. That could safe you some time during doing exercises.

Unfortunatelly I can’t write about the kind of questions you will need to deal with but If you are well prepeared and spent several hours in front of vSphere client it should be so terrible 😉 The biggest enemy on the exam is time. That’s why I recommend to do not loose much time on a question for which you don’t know the answer. It’s better to move on and if there is enought time back to it at the end.

I wish you all who are going to take the exam in near future, good luck.