What does a LUN represent in a SAN configuration?
LUN stands for “Logical Unit Number”. It is a virtual address to a device in a SCSI environment. The short version here is that if you have a SCSI RAID device, each associated volume will have its own LUN assignment.
What is SAN configuration?
Shared SAN configurations are defined as hosts that are attached to both ONTAP storage systems and other vendors’ storage systems. Accessing ONTAP storage systems and other vendors’ storage systems from a single host is supported as long as several requirements are met.
What is LUN in storage system?
In computer storage, a logical unit number, or LUN, is a number used to identify a logical unit, which is a device addressed by the SCSI protocol or by Storage Area Network protocols that encapsulate SCSI, such as Fibre Channel or iSCSI.
What is difference between LUN and volume?
A LUN is a logical volume from the point of view of the storage. From the client point of view the LUN it is a disc volume that can be partitioned. Volume is a generic term. It means a contiguous storage area.
What is a LUN for dummies?
In simple terms, a logical unit number (LUN) is a slice or portion of a configured set of disks that is presentable to a host and mounted as a volume within the OS.
Is a LUN the same as a partition?
A storage system partitions physical disks into parts with logical addresses and allows hosts to access the parts. Such a partition is called a LUN.
What is SAN and Nas?
NAS is a single storage device that serves files over Ethernet and is relatively inexpensive and easy to set up, while a SAN is a tightly coupled network of multiple devices that is more expensive and complex to set up and manage. …
Why LUN is used?
LUNs are used to identify subsets of data in a disk so that the computing devices using them can execute operations.
What is the meaning of LUN?
Stands for “Logical Unit Number.” LUNs are used to identify SCSI devices, such as external hard drives, connected to a computer. Each device is assigned a LUN, from 0 to 7, which serves as the device’s unique address. For example, a single hard drive may be partitioned into multiple volumes. …
What is LUN and Datastore?
A LUN is a logical volume on a storage system, which usually is presented to one ore more hosts. A datastore is a partition on a disk or LUN which is formatted with VMware’s VMFS filesystem.
How is a LUN assigned to a SCSI device?
LUN setup varies by system. A logical unit number is assigned when a host scans an SCSI device and discovers a logical unit. The LUN identifies the specific logical unit to the SCSI initiator when combined with information such as the target port identifier.
Where does the IBM 2145 SAN Volume Controller sit?
The IBM 2145 SAN Volume Controller (SVC) is an inline virtualization or “gateway” device. It logically sits between hosts and storage arrays, presenting itself to hosts as the storage provider (target) and presenting itself to storage arrays as one big host (initiator). SVC is physically attached to one or several SAN fabrics.
How is a LUN used in a storage device?
A LUN can be migrated within and between storage devices, as well as copied, replicated, snapshotted and tiered. A virtual LUN can be created to map to multiple physical LUNs as well as to virtualize capacity, which can be created in excess of the physical space available.
How is a LUN related to a logical unit?
In any case, the logical unit is treated as if it is a single device and is identified by the logical unit number. The capacity limit of a LUN varies by system. A LUN is central to the management of a block storage array in a storage-area network ( SAN ).