Moving from the physical server world to a virtual infrastructure requires adherence to industry best practices
for virtualization. Best practices include activities and procedures that create outstanding results in a given situation. These practices can then be efficiently and effectively adapted to other situations. Here are 10 best practices for introducing server virtualization in your environment.
1. Virtualize something! Microsoft, VMware Inc. and XenSource Inc. all offer a free version of their virtualization software packages. However, all vendors require a host operating system, and XenSource requires Intel Virtualization Technology to host Windows-based virtual machines.
2. Pay attention to hardware compatibility lists. When deploying virtualization technologies in a production environment, be sure all host hardware is on the virtualization software vendor's hardware compatibility list.
3. Customize file management. Guest virtual machine (VM) file management can get messy. Use a common sense naming convention for guest VMs and document each new VM. Virtualization software can use cryptic file and directory names during the guest VM creation process. Customize all VM files to reflect the name of the host, and place all files related to a VM in a single directory.
4. For security's sake, limit host console access and guest VM management to only those that need it. You don't want to lose a VM to careless clicking. Don't forget to use encryption and active control lists for host management ports as well.
5. Research server activity. Every server is not a candidate for virtualization. Capture some utilization statistics on the four core resources: processor, memory, network and storage prior to converting a physical server to a virtual machine. Physical servers with low to moderate activity across the four resources are excellent candidates for virtualization.
6. Set performance goals. When loading-up a host server with VMs, 60% to 80% total utilization is a reasonable target for maintaining overall host and guest virtual machine performance and high ROI.
7. The command line interface is your best friend. Learn the command line interface (CLI) supporting your virtualization software to take advantage of powerful and scriptable commands to perform such tasks as backing up, rebooting and to power down or power on guest VMs.
8. Virtual machine management trick. Use separate physical Ethernet interfaces for access to the host's console and high network I/O guest VMs. Virtual machines with low network I/O can easily share Ethernet interfaces without systems taking a performance ding.
9. Clustering: Don't think twice. Don't hesitate to take advantage of hybrid clustering for business continuity purposes. Even when a high utilization physical server implodes, a slow VM is better than nothing at all.
10. Cash in on iSCSI: VMs and iSCSI go hand-in-hand. Moreover, if you have blade servers, iSCSI is an affordable and good performing option to high-cost traditional SANs. Not only do open source operating systems like Fedora come with an iSCSI initiator and target, so does Microsoft's storage server. Lastly, iSCSI allows for high availability backups with regard to business continuity planning.
Erick Halter is the co-author of Virtualization: From the desktop to the enterprise.