Allocated space: The actual amount of capacity that is provisioned to a storage resource (such as a file system, LUN, or VMware datastore) from the storage pool, not including snapshots and thin clones. For thick provisioned storage resources, the allocated space is equal to the requested capacity. For thin provisioned storage resources, the allocated space is the capacity that is currently provisioned from the storage pool, which could be less than the requested capacity of the storage resource.
File system: A storage resource that can be accessed through file sharing protocols such as SMB or NFS.
Fully Automated Storage Tiering for Virtual Pools (FAST™ VP): A feature that relocates data to the most appropriate disk type depending on activity level to improve performance while reducing cost.
FAST Cache: A feature that allows Flash disks to be configured as a large capacity secondary cache for the Pools on the system.
NAS server: A Dell Unity storage server that uses the SMB, NFS, or FTP/SFTP protocols to catalog, organize, and transfer files within designated file system shares. A NAS server, the basis for multi-tenancy, must be created before you can create file-level storage resources such as file systems or VMware file datastores.
Network File System (NFS): An access protocol that enables users to access files and folders on a network. Typically used by Linux®/Unix hosts.
Non-base allocated space: The amount of pool space used for the snapshot and thin clones, if applicable. This is displayed at the pool level.
Operating Environment (OE): The software running on the All Flash, Hybrid, or Dell UnityVSA system.
Oversubscription: A storage provisioning method that allows administrators to provision more capacity than may be physically available in a particular storage pool. When thin provisioned storage resources are associated with a common storage pool, they can potentially request (or subscribe to) more storage capacity than the storage pool contains. Administrators can then add more drives to the system or assign more drives to the storage pool as needed. Hosts connected to thin provisioned storage resources are unaware of the pool oversubscription. They see the subscribed (or maximum) size for each thin provisioned storage resource, not the current allocated size.
Server Message Block (SMB): An access protocol that allows remote file data access from clients to hosts on a network. This is typically used in Microsoft® Windows® environments.
Size: The client visible size of a storage resource, as set at the time of creation or afterward, regardless of the actual amount of space consumed by the storage resource from the pool (see Total Pool Space Used). Size may be larger than the actual allocated size for thinly provisioned storage resources, forming the basis for overprovisioning.
Snapshot: A point-in-time view of data stored on a storage resource. A user can recover files from a snapshot, restore a storage resource from a snapshot, or provide access to a host. Snapshots can be read-only or read/write.
Storage pool: A collection of disk drives configured with a particular storage profile. The storage profile defines the type of disks used to provide storage and the type of RAID configured on the disks. The storage pool’s configuration defines the number of disks and quantity of storage associated with the pool. Dell Unity uses unified storage pools for both block and file storage resources.
Storage processor (SP): A storage node that provides the processing resources for performing storage operations and servicing I/O between storage and hosts.
Thin provisioned storage resource: A storage resource (such as a file system, LUN, or VMware datastore) that is not fully allocated from the storage pool. The client can see the full size of the storage resource even though only a portion of the storage resource is allocated from the storage pool.
Total pool space used: The total amount of space consumed by the storage resource on the pool, including all overhead, metadata, snapshots, and thin clones. This is displayed at the pool level.
Unisphere CLI (UEMCLI): The command-line interface for managing Dell Unity storage systems.
Unisphere: The HTML5 web-based user interface for managing Dell Unity storage systems.
Used space: The amount of space in a file system that is consumed by the clients. This relates to the amount of data users have stored in the file system.
Virtual Volumes (vVols): A VMware storage framework which allows VM data to be stored on individual volumes. This allows for features such as snapshots to be applied at a VM-granularity and provides Storage Policy Based Management (SPBM).
VMware vSphere Storage APIs Array Integration (VAAI): A set of APIs to enable communication between VMware vSphere ESXi™ hosts and storage devices. The APIs define a set of storage primitives that enable the ESXi host to offload certain storage operations to the array, which reduces resource overhead on the ESXi hosts and can significantly improve performance for storage-intensive operations such as storage cloning, zeroing, and so on. The goal of VAAI is to help storage vendors provide hardware assistance to speed up VMware I/O operations that are more efficiently accomplished in the storage hardware.