To understand the concepts in this document, you might need to know the terms defined here.
General storage system terminology
- Storage systems that run Data ONTAP are sometimes referred to as filers, appliances, storage
appliances, or systems. The name of the FilerView graphical user interface for Data ONTAP reflects one of these common usages.
- Controller or storage controller refers to the component of a storage system that runs the Data ONTAP operating system and controls its disk subsystem. Controllers or storage controllers are also sometimes called storage appliances, appliances, storage engines, heads, CPU modules, or controller modules.
Active/active configuration terminology
- An active/active configuration is a pair of storage systems configured to serve data for each other if one of the two systems becomes impaired. In Data ONTAP documentation and other information resources, active/active configurations are sometimes also referred to as clusters or active/active pairs.
- When in an active/active configuration, systems are often called nodes. One node is sometimes called the local node, and the other node is called the partner node or remote node.
- Standard active/active configuration refers to a configuration set up so that one node automatically takes over for its partner when the partner node becomes impaired.
- Mirrored active/active configuration is similar to the standard active/active configuration, except that there are two copies, or plexes, of the data. This is also called data mirroring.
- Fabric-attached MetroCluster refers to an active/active configuration
running the syncmirror_local and cluster_remote licenses, where the nodes are attached to two pairs of Fibre Channel switches, and they are separated by more than 500 meters.
- Stretch MetroCluster refers to an active/active configuration
running the syncmirror_local and cluster_remote licenses, where the nodes are separated by up to 500 meters, and no switches are used between the nodes. This configuration is also sometimes called a nonswitched MetroCluster.
- Controller failover, also referred to as cluster failover or CFO, refers to the technology that enables two storage systems to take over each other's data, thus improving data availability.
- Remote storage refers to the storage that is accessible to the local node, but is at the location of the remote node.
Storage hardware terminology
- FC HBA for Disk or FC HBA refers to the Fibre Channel host bus adapter that connects the node to the switch or to the disks.
- Disk shelf refers to a unit of the disk subsystem component of the storage system.
- LRC (Loop Resiliency Circuit) disk shelf module refers to a component that keeps the Fibre Channel-Arbitrated Loop (FC-AL) intact during the addition and removal of disks within a disk shelf. It also contains the enclosure services processor, which communicates the environmental data of the disk shelf.
- ESH (Embedded Switching Hub) disk shelf module refers to a component that provides a means of managing an FC-AL loop in an intelligent manner, such that a single drive failure does not take down the loop. It also contains the enclosure services processor, which communicates the environmental data of the disk shelf.
- ESH2 disk shelf module refers to a second-generation ESH module.
- ESH4 disk shelf module refers to a third-generation ESH module.
- AT-FCX refers to an enhanced FC-AL to Serial ATA (SATA) bridge used in some disk shelves.
- The term type means pressing one or more keys on the keyboard.
- The term enter mean pressing one or more keys on the keyboard and then pressing the Enter key, or clicking in a field in a graphical interface and typing information into it.