HP StorageWorks Director 2/64 Installation Manual page 23

Director 2/64 Installation Guide
Domain ID assignment—Each director in a fabric is identified by a unique
domain ID that ranges from 1 through 31. A domain ID of 0 is invalid. If two
operational fabrics join, they determine if any domain ID conflicts exist
between the fabrics. If one or more conflicts exist, the E_Ports that form the
interswitch link (ISL) segment to prevent the fabrics from joining.
Zoning—In a multi-switch fabric is configured on a fabric-wide basis, and a
change to the zoning configuration is applied to all directors and switch
elements in the fabric. To ensure zoning is consistent across a fabric, the
following rules are enforced when two fabrics (zoned or unzoned) join:
— Fabric A unzoned and Fabric B unzoned—The fabrics join
successfully, and the resulting fabric remains unzoned.
— Fabric A zoned and Fabric B unzoned—The fabrics join successfully,
and fabric B automatically inherits the zoning configuration from
fabric A.
— Fabric A unzoned and Fabric B zoned—The fabrics join successfully,
and fabric A automatically inherits the zoning configuration from
fabric B.
— Fabric A zoned and Fabric B zoned—The fabrics join successfully only
if the zone configurations can be merged. If the fabrics cannot join, the
connecting E_Ports segment and the fabrics remain independent.
Zone configurations for two fabrics are compatible (the zones can join) if the
active zone set name is identical for each fabric, and if zones with the same
name have identical elements.
Port segmentation—When an ISL activates, directors exchange operating
parameters to determine if they are compatible and can join to form a single
fabric. If they are incompatible, the connecting E_Port at each director
segments to prevent the creation of a single fabric. A segmented link transmits
only Class F traffic; the link does not transmit Class 2 or Class 3 traffic. The
following conditions cause ports to segment:
— Incompatible operating parameters—Either the resource allocation
timeout value (R_A_TOV) or error detect timeout value (E_D_TOV) is
inconsistent between directors. To prevent E_Port segmentation, the same
E_D_TOV and R_A_TOV must be specified for each director.
— Duplicate domain IDs—One or more domain ID conflicts are detected.
— Incompatible zoning configurations—Zoning configurations for the
directors are not compatible.
Overview
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