What is a LUN in ONTAP and how is it used?

• A. A LUN is a logical unit of storage presented to a host for block-level access, typically via iSCSI or FC.
• B. LUN stands for Local User Network.
• C. LUN is a file-level storage unit accessed via NFS.
• D. LUN is a metadata unit used for backups.

Answer: (A)

A LUN in ONTAP is a block-level storage object that a host sees as a disk. It is created on a NetApp volume and exposed to hosts using block protocols such as iSCSI or Fibre Channel. The host can then format and use the LUN just like any other disk, performing reads and writes against that raw storage. LUNs are mapped to initiator groups to control which hosts can access them, making them a primary way to provision storage for servers and applications in ONTAP. This is different from file-level storage (like NFS) or metadata usage, which is why the other options don’t fit.