Understanding the Power of VMware vApps The power of VMware vApps is something that I think most VMware Admins still overlook simply because they haven’t taken the time to learn more

Introduction

The power of VMware vApps is something that I think most VMware Admins still overlook simply because they haven’t taken the time to learn more. I believe that once you learn more about vApps, you’ll see that they offer amazing portability and power which you’ll want to use in your VMware infrastructure.

In the past, I have created a couple of videos on vApps. They are Great New vApp / OVF 1.0 Features in vSphere 4 and What are VMware vApps?. These videos offer good information on the concept of a vApp but they are also based on vSphere 4 and there have been a number of improvements since then. Thus, let’s start from the beginning on what a vApp is and how the latest features can help you, in vSphere 5.

What is a VMware vApp?

A vApp is a container for virtual machines that offers resource controls and management for the virtual machines that are inside. Think of a vApp as a portable, self-contained box that holds multiple virtual machines that make up a multi-tiered application (like a web server, database, and security server), including all custom network configurations.

vApps offer:

  • Container for multiple virtual machines
  • Resource controls for the VMs inside the container
  • Network configurations contained inside
  • Portability of the vApp such that everything can be contained and transferred to another virtual infrastructure
  • Entire vApps can be powered on, powered off, suspended, or shutdown
  • Entire vApps can be cloned

Probably the best way to understand vApps is to create one so let’s learn how.

Creating a vApp

Creating a vApp is easy. To do it, in your vSphere client (connected to vCenter), click on File, go to New, and click on vApp, as you see in Figure 1. Alternately, you can press Control-A.


Figure 1

This will bring up the New vApp Wizard. The first thing you need to do in this wizard is to create a name for the vApp In my case, I simply called it “Client-Server-App” and clicked Next.


Figure 2

Next, you need to configure the resource allocation for the vApp. At this point, the only resource allocations available are either CPU or memory. The resource configurations are just like a resource pool as a vApp really contains a resource pool. vApp resources use the same shares, reservations, and limits that regular resource pools use. Notice how I went ahead and reserved 4000Mhz of vCPU and 6000MB (6GB) of vRAM for the VMs that will be inside the vApp resource pool.


Figure 3

Finally, a review before creating the vApp, as shown in Figure 4. After reviewing, click Finish.

Linux Centos, History A short bio about Linux Centos

CentOS is a Linux distribution that attempts to provide a free, enterprise-class, community-supported computing platform functionally compatible with its upstream source, Red Hat Enterprise Linux (RHEL).In January 2014, CentOS announced the official joining with Red Hat while staying independent from RHEL, under a new CentOS governing board.

The first CentOS release in May 2004, numbered as CentOS version 2, was forked from RHEL version 2.1AS.Since the release of version 7.0, CentOS officially supports only the x86-64 architecture, while versions older than 7.0-1406 also support IA-32 with Physical Address Extension (PAE). As of December 2015, AltArch releases of CentOS 7 are available for the IA-32 architecture, Power architecture, and for the ARMv7hl and AArch64 variants of the ARM architecture.

CentOS versionRelease date
CentOS version Release date – From Wikipedia – CentOS version Release date

 

How to enable detailed boot on Linux Centos 6.x CentOS 6 uses the Fedora-style graphical boot screen, on this guite we show you how to enable Detailed Boot Linux

If you notice, Linux Centos, starting from 6.x (6.1, 6.2, 6.3, 6.4, 6.4, 6.6, 6.7 and 7.x) uses Fedora-style graphical boot screen, with the three blue/white bars at the bottom merging into one.

Boot Centos Bar
Boot Centos Bar

 

 

 

So, if you need detailed-classic linux boot sequence, is enought press ‘esc’ to enable it.

Detailed Boot Linux Centos
Detailed Boot Linux Centos

How to enable Performance data when is not available from VMware vCenter Fix Performance data when is not available for an entity by CLI

Details
When connected with VMware Infrastructure (VI) Client to the ESXi/ESX host, performance graphs are not available.
You see an error similar to:

  • Performance data is currently not available for this entity

Solution
This issue occurs when the time is not synchronized between the VI Client host and the ESXi/ESX host.

To resolve this issue, ensure there is no time differences between the VI Client host and the ESXi/ESX host.

Run these commands:

For ESXi:
/etc/init.d/ntpd restart

and

/etc/init.d/vpxa restart