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Understand CPU Virtualization: At this time m ost modern CPU architectures support different levels of privilege, called rings. Ring 0 has the highest privilege; processes running in this ring are referred to as running in supervisor or kernel mode. Processes running in higher rings are referred to as running in user mode. The higher the number of the ring, the less privilege a process running in this ring has. An x86-based CPU supports four levels of privilege, but in practice only rings 0 and 3 are used. In Linux and Windows, the operating system kernel and hardware drivers run in Ring 0, and user processes run in Ring 3. Only processes in Ring 0 can access hardware. If a process in a higher ring needs to access hardware, such as the hard disk, it has to use the APIs of the kernel. Here is the demonstration of  CPU Rings with Native Operating System: When we will use Xen, the Xen Hypervisor runs in Ring 0, and the operating system kernel is moved to Ring 1. This...

Setup iSCSI Target & Initiator on CentOS 6 What is iSCSI? iSCSI is a network protocol defined to allow scsi commands over TCP/IP stack, allowing to hosts I/O block operations like a device storage attached locally. With iSCSI we have two diffrent basic concepts: iSCSI initiator: we can say it "scsi client", and it can be connected to the server in two ways: Software initiator: Normally is implemented as a module that will used by the network interface and emulate scsi devices. this is the most implementation. Hardware initiator: It use a dedicated hardware to implement iSCSI. The work load of the iSCSI process is handled by this hardware. iSCSI target: This is a references of storage resource located in a iSCSI server. The servers (targets) have logical units or LUN, that is a number to identify a logical unit storage in the server and the client (initiator) negotiates the connection of a specified LUN with the target. In a iSCSI network each iSCSI ele...

Generally we always copy the content in Virtual Machine via network or direct copy in Virtual Machine. We also have a method to access VMware Workstation File in Linux, Right now i am using Ubuntu Linux, so i am going to access .VMDK file at Ubuntu 13.10, but this is the same method for all Linux distributions. To access ".VMDK" file in Ubuntu, First of all we need to verify "vmware-mount" command. This command is already provided by VMware Workstation or VMware Server, But in case if this file is not there, then we need to install the additional package during the VMware Workstation installation. Here are the steps to access .VMDK file in Ubuntu. # vmware-mount -p /home/geo/vmware/my-disk.vmdk         This command show us the mount point within this disk. # vmware-mount /home/geo/vmware/my-disk.vmdk /mnt This command will mount our ".vmdk" disk to /mnt directory. # cd /mnt        Now we can copy the data from this disk...