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NAME

san - Glossary for NetApp specific SAN terms

DESCRIPTION

The san glossary is meant to provide users with short definitions and examples of terminology used by NetApp in its unified storage offering. These terms are a supplement to the SNIA dictionary at http://www.snia.org/education/dictionary/ which provides a more comprehensive list of SAN terms.

GLOSSARY

FCP ( Fibre Channel Protocol )

A licensed service on the filer that enables you to export LUNs to hosts using the SCSI protocol over a Fibre Channel fabric.

HBA ( host bus adapter )

An I/O adapter that connects a host I/O bus to a computer's memory system. HBA is the preferred term in SCSI contexts. The HBA might be an FCP adapter or an iSCSI adapter. An adapter might have multiple ports.

host

A system that is accessing data on a filer as blocks. The host accesses data using the FCP or iSCSI protocols.

igroup ( Initiator Group )

A collection of the unique identifiers, either iSCSI node names or WWPNs of initiators (hosts). Initiator groups can have multiple initiators, and multiple initiator groups can have the same initiator. To make the LUNs accessible to hosts, you use the lun map command to map LUNs to an initiator group. By mapping LUNs to the hosts listed in the initiator group, you allow access to the LUNs to these hosts. If you do not map a LUN, the LUN is not accessible to any hosts. The following example shows an FCP initiator group with two initiators:

  igroup_1 (FCP) (ostype: solaris):
            10:00:00:00:c7:2c:36:3e
            10:00:00:00:c8:2c:37:g1

Initiator

The system component that originates an I/O command over an I/O bus or network.

iSCSI

A licensed service on the filer that enables you to export LUNs to hosts using the SCSI protocol over TCP/IP.

LUN ( logical unit number )

The SCSI identifier of a logical unit within a target.

LUN clone

A complete copy of a LUN, which was initially created to be backed by a LUN or a file in a snapshot. The clone creates a complete copy of the LUN and frees the snapshot, which can then be deleted. For more information, see the lun create -b command on the man page for na_lun.

LUN ID

The ID that the filer exports for a given LUN. The LUN ID is mapped to an initiator group to enable host access. For a Windows system LUN 0 must exist so that the host will recognize additional LUNs. The following example shows a LUN with an ID of 6:
  LUN path              Mapped to          LUN ID
  ---------------------------------------------------
  /vol/vol10/fcpdb.lun    igroup_1             6

LUN path

The path to a LUN on the filer. The following example shows a LUN path:

  LUN path              Mapped to          LUN ID
  ---------------------------------------------------
  /vol/vol10/fcpdb.lun    igroup_1             6

LUN serial

The unique serial number for a LUN as defined by the filer. You use the lun serial command to change this number. The following example shows a LUN serial number:

  filer_1> lun show -v /vol/vol0/fcpdb
       /vol/vol0/fcpdb           10m (10485760)  (r/w, online)
       Serial#: Och/RngAi4p4
       Share: none
       Space Reservation: enabled
       Multiprotocol Type: image

map

To create an association between a LUN and an initiator group. A LUN mapped to an initiator group is exported to the nodes in the initiator group (WWNN or iqn) when the LUN is online. LUN maps are used to secure access relationships between LUNs and the host.

online

Signifies that a LUN is exported to its mapped initiator groups. A LUN can be online only if it is enabled for read/write access.

offline

Disables the export of the LUN to its mapped initiator groups. The LUN is not available to hosts.

share

Allows the LUN's data be accessible through multiple file protocols such as NFS and FCP. One can share a LUN for read or write access, or all permissions.

SPACE_RESERVATIONS

Required for guaranteed space availability for a given LUN with or without snapshots.

target

The system component that receives a SCSI I/O command.

WWN ( World Wide Number )

A unique 48 or 64-bit number assigned by a recognized naming authority (often through block assignment to a manufacturer) that identifies a connection to the storage network. A WWN is assigned for the life of a connection (device).

WWNN ( World Wide Node Name )

Every node has a unique World Wide Node Name (WWNN), which Data ONTAP refers to as a Fibre Channel Nodename, or, simply, node name. NetApp assigns a WWNN to a filer based on the serial number of its NVRAM. The WWNN is stored on disk. The WWNN is a 64-bit address represented in the following format: nn:nn:nn:nn:nn:nn:nn:nn, where n represents a hexadecimal value.

WWPN ( World Wide Port Name )

Each Fibre Channel device has one or more ports that are used to connect it to the SAN network. Each port has a unique World Wide Port Name (WWPN), which Data ONTAP refers to as an FC Portname, or, simply, port name. The WWPN is a 64-bit address represented in the following format: nn:nn:nn:nn:nn:nn:nn:nn, where n represents a hexadecimal value.

SEE ALSO

na_fcp(1), na_igroup(1), na_iscsi(1), na_lun(1)


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