Saturday, June 23, 2007

Vmware - Virtual OS

Vmware : Your Virtual OS which can run as many OS inside your Physical Host.
Products :
1) VMware workstation: VMware Workstation allows one physical machine to run two
or more operating systems simultaneously.
It can create .vmdk files as hard disks;
VMware Workstation also allows the testing of LiveCDs without first burning them onto
physical discs or rebooting the computer
One can also take multiple successive snapshots of an operating system running under
VMware Workstation.
Each snapshot allows you to roll back the virtual machine to the saved status at any time.
2) VMware Player: VMware Player available free of charge to run guest virtual machines
produced by other VMware products: it cannot itself create new virtual machines.

Based on answers you can create Guest OS, from the Internet.

Here are some websites that allow you to do this:

VM Builder


3) VMware Server (formerly VMware GSX Server):
VMware Server can create, edit, and play virtual machines. It uses a client-server model,
allowing remote access to virtual machines, at the cost of some graphical performance (and 3D support).
In addition to the ability to run virtual machines created by other VMware products,
it can also run virtual machines created by Microsoft Virtual PC.
Simple example of setting up RedHat to run on Windows :
Download VMware Player
Create a Guest OS from EasyVMX!
Once you create a Guest OS , open Vmware Player and point it to the .vmx file
Exploring .VMX File :
1) A hash (or pound sign, #) are used for comments. Thus, anything that starts with a # sign is ignored and considered a comment.
2) The displayName is what is used on the VMware Tab to identify the virtual machine.
This can be whatever you want to make it but I suggest something short that still uniquely
identifies the virtual machine. In this case, our virtual machine is called "WinXP".

3) The memory of the virtual machine is determined by the memsize line.

In our case, our memory is 512 because of memsize=512.

While you can set the memory to whatever size you want, it must be a multiple of 4.

4) The guestOS is one of these possible values: GUEST OS Options
5) The virtualHW.version is a required parameter.
It tells VMware what VMware version this VMX is meant for. All VMware VMX files that run on
Workstation, Player, or Server are version 4. Thus, you need virtualHW.version = "4"
6) As VMware disk drives can either be IDE or SCSI, you will see both represented in the VMX file.
The VMX doesn't tell you the size of the virtual hard drives, nor the full path.
It does tell you the name of the VMDK, VMware virtual disk file. In our case, this looks like:
ide0:0.fileName = "Windows XP Professional.vmdk"
The only 3 parameters required to make a VMX file are:
  1. virtualHW.version="4"

  2. config.version="4"

  3. guestOS="winxppro"

Other Files you Should Know :

Log files – Log files are just that- a log of virtual server activity for a single virtual server.

Here is an example of what a log file looks like:

Log files should be used only when you are having trouble with a virtual machine.

VMDK files – VMDK files are the actual hard drive for the virtual machine.

Usually you will specify that a virtual machine's disk can grow as needed.

In that case, the VMDK file will be continually growing, up to a size of 2GB. After 2GB,

subsequent VMDK files will be created.

VMEM – A VMEM file is a backup of the virtual machine's paging file.

It will only appear if the virtual machine is running, or if it has crashed.

VMSN & VMSD files – these files are used for VMware snapshots.

A VMSN file is used to store the exact state of the virtual machine when the snapshot was taken.

Using this snapshot, you can then restore your machine to the same

state as when the snapshot was taken. A VMSD file stores information about snapshots (metadata).

You'll notice that the names of these files match the names of the snapshots.

NVRAM files – these files are the BIOS for the virtual machine.

The VM must know how many hard drives it has and other common BIOS settings.

The NVRAM file is where that BIOS information is stored.

VMX files – a VMX file is the primary configuration file for a virtual machine.

When you create a new virtual machine and answer questions about the operating system,

disk sizes, and networking, those answers are stored in this file.

As you can see from the screenshot below, a VMX file is actually a simple text file

that can be edited with Notepad. Here is the "Windows XP Professional.vmx" file from the directory listing, above: