My IT Blog

Author:     Johan  De  Gelas Page 1 Introduction First dual-core in 2005, then quad-core in 2007: the multi-core snowball is rolling. The desktop market is still trying to find out how to wield all this power; meanwhile, the server market is eagerly awaiting the octal-cores in 2009. The difference is that the server market has a real killer application, hungry for all that CPU power: virtualization. While a lot has been written about the opportunities that virtualization brings (consolidation, hosting legacy applications, resource balancing, faster provisioning...), most publications about virtualization are rather vague about the "nuts and bolts". We talked to several hypervisor architects at VMWorld 2008. In this article, we'll delve a bit deeper as we look to understand the impact of virtualization on performance. Performance? Isn't that a non-issue? Modern virtualization solutions surely do not lose more than a few percent in performance, right? We'l

There are lot of forum links , articles which explains the booting process of Linux.  I am not going to tell any thing different but I would like to show my point of perspective on some extra details of the  Linux Booting procedure. Here we go ! The stages involved in Linux Booting Process are: BIOS Boot Loader     - GRUB Init Runlevel scripts BIOS This is the first thing which loads once you power on your machine. When you press the power button of the machine, CPU looks out into ROM for further instruction. The ROM contains JUMP function in the form of instrucion which tells the CPU to bring up the BIOS BIOS determines all the list of bootable devices available in the system. Prompts to select bootable device which can be Hard Disk, CD/DVD-ROM, Floppy Drive, USB Flash Memory Stick etc (optional) Operating System tries to boot from Hard Disk where the MBR contains primary boot loader. Boot Loader  It is the first sector of the Hard Disk with a siz

1. What is a Hypervisor? It is a program that allows multiple operating systems to share a single hardware host. Each operating system appears to have the host's processor, memory, and other resources all to itself. However, the hypervisor is actually controlling the host processor and resources, allocating what is needed to each operating system in turn and making sure that the guest operating systems (called virtual machines) cannot disrupt each other. 2. What is the hardware version used in VMware ESXi 5.5? Version 10 Below is the table showing the different version of hardware used in different VMware products along with their release version Virtual Hardware Version Products 10 ESXi 5.5, Fusion 6.x, Workstation 10.x, Player 6.x 9 ESXi 5.1, Fusion 5.x, Workstation 9.x, Player 5.x 8 ESXi 5.0, Fusion 4.x, Workstation 8.x, Player 4.x 7 ESXi/ESX 4.x, Fusion 2.x/3.x Workstation 6.5.x/7.x,Player 3.x 6 Workstation 6.0.x 4 ACE 2.x, ESX 3

Syntax : 1..<N> | Foreach {  New-VM -vmhost <ESX_HOST> -Name <VM_NAME> -Template <TEMPLATE> -Datastore <DATASTORE> [-OtherOptions]  }  Where: <N> is the number of VMs you need to deploy. <ESX_HOST> is the host where you will deploy your VMs <TEMPLATE> is the template from which your VMs will be created <DATASTORE> is the datastore that will contain your VMs [-OtherOptions] are additional options that can be used in conjunction with New-VM command. As you can see it's really basic, but New-VM cmdlet is really powerful and it has a lot of options. To go through all on New-VM options: Get-Help New-VM -Detailed Here's how I used it today for deploying 6 VMs that will be Oracle RAC nodes. Open a text editor and paste this code in it saving file with .ps1 extension. 1..2 | Foreach {  New-VM -vmhost esx1.testdomain.com -Name RAC$_ -Template OL6 -Datastore datastore1  }  3..4 | Foreach {  New-VM -vmhost esx