Once you go graphical with KVM's Virtual Machine Manager, you might never go back to the command line.
A VM’s “Details” refer to the specifics of the VM’s hardware configuratiion (i.e. CPUs, Memory, Boot Options, Disks, NICs, Mouse and Display). The Details allow you to change any of the hardware components in your system. For example, you may change the number of CPUs for a VM, the amount of RAM, add disks or NICs. You can also remove hardware components. See Figure 4.
Figure 4: Virtual Machine Details (CPU Configuration)
The Console option opens a VNC connection to your VM and places you at a login prompt as shown in Figure 5. This VNC connection is independent of any other connection made to the VM.
Figure 5: VNC Virtual Machine Console
Though a bit spartan in design details, VMM offers some advanced management features such as the ability to create and manage new Virtual Networks and to create and manage new VMs. Both activities step you through simple wizards to help you use KVM virtualization faster and with fewer mistakes. Compared to the command line, VMM allows you to perform these advanced functions with little or no training. However, the command line enables you to automate your VM creation and management. Used together, they create a powerful and cohesive virtualization solution that rivals its expensive alternatives.
To manage an existing Virtual Network, click Edit from the VMM main menu and select Host Details from the dropdown menu. Here, you’ll see any current Virtual Network, such as the one shown (default) in Figure 6.
Figure 6: Viewing Virtual Network Information for a KVM Host
To launch the Create a new virtual network wizard, click the Add button and follow the instructions. The steps to create a new virtual network are as follows: Name the new virtual network, set the IPv4 address space, set the address range for DHCP allocations and whether to forward traffic to a physical adapter or to isolate the virtual network.
Creating a new VM with VMM is very easy. In VMM, select the KVM host system and click the New button to launch the Create a new virtual system wizard. The steps to create a new VM with the wizard are: Name the virtual system, decide to fully virtualize the new VM or use paravirtualization, identify the installation source (ISO or CD/DVD), make decisions for VM disk storage and allocate memory and CPU for the new VM.
The KVM Virtual Machine Manager has the advantage of getting users up to speed with KVM much faster than its command line counterpart. Experienced and new administrators alike will appreciate the lightweight VMM interface and easy-to-use wizards. Yes, the command line is more powerful and flexible but for those of you who just want to create and manage a few VMs, VMM is a good answer. You may also find that discovering KVM management via VMM will help you at the command line as well by using the automatically created XML VM definition files as templates. As stated earlier, the combination of VMM and command line utilities provides an extremely powerful virtualization technology.
Kenneth Hess is a Linux evangelist and freelance technical writer on a variety of open source topics including Linux, SQL, databases, and web services. Ken can be reached via his website at http://www.kenhess.com
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