HP Fabric OS 7.1.0, Руководство администратора

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52 Fabric OS Administrator’s Guide
53-1002745-02
Device login
1
Fabric login process
A device performs a fabric login (FLOGI) to determine if a fabric is present. If a fabric is detected
then it exchanges service parameters with the fabric controller. A successful FLOGI sends back the
24-bit address for the device in the fabric. The device must issue and successfully complete a
FLOGI command before communicating with other devices in the fabric.
Because the device does not know its 24-bit address until after the FLOGI, the source ID (SID) in
the frame header of the FLOGI request are zeros (0x000000).
Port login process
The steps in the port initialization process occur as the result of a protocol that functions to
discover the type of device connected and establish the port type and negotiate port speed. See
“Port Types” on page 84 for a discussion of available port types.
The Fibre Channel protocol (FCP) auto discovery process enables private storage devices that
accept the process login (PRLI) to communicate in a fabric.
If device probing is enabled, the embedded port performs a PLOGI and attempts a PRLI into the
device to retrieve information to enter into the name server. This enables private devices that do
not perform a FLOGI, but accept a PRLI, to be entered in the name server and receive full fabric
access.
A fabric-capable device registers its information with the name server during a FLOGI. These
devices typically register information with the name server before querying for a device list. The
embedded port still performs a PLOGI and attempts a PRLI with these devices.
If a port decides to end the current session, it initiates a logout. A logout concludes the session and
terminates any work in progress associated with that session.
To display the contents of a switch’s name server, use the nsShow or nsAllShow command.
For more information about these commands, refer to the
Fabric OS Command Reference .
RSCNs
A Registered State Change Notification (RSCN) is a notification frame that is sent to devices that
are zoned together and are registered to receive a State Change Notification (SCN). The RSCN is
responsible for notifying all devices of fabric changes. The following general list of actions can
cause an RSCN to be sent through your fabric:
•
A new device has been added to the fabric.
•
An existing device has been removed from the fabric.
•
A zone has changed.
•
A switch name has changed or an IP address has changed.
•
Nodes leaving or joining the fabric, such as zoning, powering on or shutting down a device, or
zoning changes.
NOTE
Fabric reconfigurations with no domain change do not cause an RSCN.