Home > Storage > PowerVault > Guides > Dell PowerVault ME5 Series: VMware vSphere Best Practices > Virtual and linear storage
PowerVault ME5 arrays use two storage technologies that share a common user interface: the virtual method and the linear method.
Linear method: This method maps logical host requests directly to physical storage. Sometimes, the mapping is one-to-one, while usually, the mapping spans groups of physical storage devices or slices of them. While the linear method of mapping is highly efficient, it lacks flexibility. This makes it difficult to alter the physical layout after it is established.
Virtual method: This method maps logical storage requests to physical storage (disks) through a layer of virtualization. Logical host I/O requests are first mapped onto pages of storage, and then each page is mapped onto physical storage. Within each page, the mapping is linear, but there is no direct relationship between adjacent logical pages and their physical storage. A page is a range of contiguous logical block addresses (LBAs) in a disk group, which is one of up to 16 RAID sets that are grouped into a pool. Thus, a virtual volume as seen by a host represents a portion of storage in a pool. You can create multiple virtual volumes in a pool, sharing its resources. This practice enables a high level of flexibility and the most efficient use of available physical resources.
Some advantages of using virtual storage include the following:
Virtual storage provides the foundation for data-management features such as thin provisioning, automated tiered storage, read cache, and the quick disk rebuild feature. Because these storage features are valuable in most environments, we recommend using virtual storage when deploying VMware vSphere environments. Linear storage pools are most suited to sequential workloads such as video archiving.
Note: You cannot use data management features in Linear Storage Mode.