work) that interconnects and presents shared pools of storage devices to multiple servers (20, n.d.). SANs are primarily used to enhance storage devices, such as disk arrays, tape libraries, and optical jukeboxes, accessible to servers SO that the devices appear to the operating system as locally attached devices. A SAN typically has its own network of storage devices that are generally not accessible through the local area network (LAN) by other devices (21, n.d.). Storage virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization helps the storage administrator perform the tasks of backup, archiving, and recovery more easily-and in less time-by disguising the actual complexity of a SAN (22, n.d.). Many service providers will also deploy Ceph, an open-source software solution to provide dis- tributed object store and file-based storage designed to provide excellent performance, reliability, and scalability. Ceph provides object storage and block storage under a unified solution. Listed below are some benefits of NFVI storage virtualization for service providers and end users alike. 4.2.4.5.1 Data Migration One of the major benefits of abstracting the host or server from the actual storage is the ability to migrate data while maintaining concurrent I/O access. The host only knows about the logical disk (the mapped logical unit number [LUN]) and SO any changes to the metadata mapping is transpar- ent to the host. This means the actual data can be moved or replicated to another physical location without affecting the operation of any client. When the data have been copied or moved, the meta- data can simply be updated to point to the new location, therefore, freeing up the physical storage at the old location. 4.2.4.5.2 Improved Utilization Utilization can be increased by virtue of the pooling, migration, and thin provisioning services. This allows users to avoid over-buying an