part of the SAN; either provides the layer of abstraction between the hosts performing the I/O and the storage controllers providing the storage capacity. The second method, called host-client, uses software running on file and application servers to detect available storage and to maintain the metadata necessary to manage them. The third method, known as in-array or embedded functionality, uses a special network controller and management software to manage different storage systems as one large resource. All methods provide the advantages of storage virtualization, which include:
▲ Easier administration as virtualized storage can be managed from a single administrative console.
▲ Storage growth can be closely monitored and managed, making upgrade planning easier.
▲ Disaster recovery is improved as storage can be more easily moved around or backed up to other locations.
▲ Data can be migrated to new storage devices without disrupting the application, since the physical storage is not directly tied to the application. This makes it easier to swap out end-of-lease equipment or to refresh old storage with newer devices.
Issues to be aware of when considering storage virtualization include:
▲ If you have heterogeneous storage devices, are they all compatible with the virtualization technology you're considering?
▲ Ensure that the storage metadata is protected and backed up.
▲ Be aware that whichever option you choose, you'll be locked into a particular vendor.
Desktop PCs are notoriously difficult to maintain as new software is installed and old applications are removed. It can be difficult to keep track of what versions of what software are installed on any given machine, and conflicts can occur among incompatible versions of different applications. Many organizations use Microsoft Terminal Services or Citrix Presentation Server to provide a managed, stable desktop environment that can be accessed using a standard PC or a less expensive thin client device. Desktop virtualization builds on this by giving the user a virtualized full client environment using a server-based hypervisor. This allows the user to have full administrative control over the desktop environment and applications. Some of the advantages of desktop virtualization include:
▲ Easy to deploy desktops to new users.
▲ Desktop machines can be less expensive PCs or thin client devices.
Was this article helpful?