General

NetApp Specific

Alignment

Tag Explanation

  • Fibre Channel Fibre Channel, or FC, is a gigabit-speed network technology primarily used for storage networking. Fibre Channel is standardized in the T11 Technical Committee of the InterNational Committee for Information Technology Standards (INCITS), an American National Standards Institute (ANSI)–accredited standards committee. Fibre Channel was primarily used in the supercomputer field, but now, has become the standard connection type for storage area networks (SAN) in enterprise storage. Despite its name, Fibre Channel signaling can run on both twisted pair copper wire and fiber-optic cables. Fibre Channel Protocol (FCP) is a transport protocol (similar to TCP used in IP networks) which predominantly transports SCSI commands over Fibre Channel networks.
  • FLOGI / PLOGI /PRLI (taken from EMC Community Network)
    • N_Portan end device connecting to a switched fabric network, such as a SCSI initiator or a SCSI target.
    • F_Port a port on a switch that provides access to Fabric Services (eg. the Fabric Nameserver & the Fabric Login Server etc)Fabric_point_2_point initialization (ie. N_Port to F_Port initialization) involves the following ordered sequence: FLOGI, PLOGI, PRLI.
    • FLOGI N_Port requests a unique 24-bit address from the Fabric Login Server (accessible via an F_port on a Fabric switch).#
    • PLOGI N_Port informs the Fabric Name Server of its personality and capabilities. For example:
      • WWNN, WWPN
      • Buffer credits for flow control
      • clock frequency ('speed capability')
      • Upper layer protocol support (eg. SCSI-3, IP)
    • PRLI Upper layer protocol communication. Well, ever since SCSI was designed and engineered (1970s, or so, previously SASI...), SCSI initiators need to discover SCSI targets. So, during PRLI, N_Port SCSI initiators discover N_Port SCSI targets (which is an opportunity for the host (maybe a UNIX host) to assign a target ID to the device path). Depending on the OS, you may be able to investigate further with commands like: egrep -i 'flogi|plogi|prli' /var/adm/messages

Previous Post Next Post