HP StorageWorks 2/16V HP StorageWorks Fabric OS 5.3.x administrator guide (569 - Page 421

A Configuring the PID format Port identifiers (called PIDs) are used by the routing and zoning services in Fibre Channel fabrics to identify ports in the network. All devices in a fabric must use the same PID format, so when you add new equipment to your SAN, you might need to change the PID format on legacy equipment. About PIDs and PID binding The PID is a 24-bit address built from three 8-bit fields: • domain • area_ID • AL_PA Many scenarios cause a device to receive a new PID; for example, unplugging the device from one port and plugging it into a different port as part of fabric maintenance, or changing the domain ID of a switch, which might be necessary when merging fabrics, or changing compatibility mode settings. Some device drivers use the PID to map logical disk drives to physical Fibre Channel counterparts. Most drivers can either change PID mappings dynamically (called dynamic PID binding) or use the WWN of the Fibre Channel disk for mapping (called WWN binding). Some older device drivers behave as if a PID uniquely identifies a device (they use static PID binding). These device drivers should be updated, if possible, to use WWN or dynamic PID binding instead, because static PID binding creates problems in many routine maintenance scenarios. Fortunately, very few device drivers still behave this way. Many current device drivers enable you to select static PID binding as well as WWN binding. You should only select static binding if there is a compelling reason, and only after you have evaluated the impact of doing so. Summary of PID formats Switches running Fabric OS 5.1.x employ these types of PID formats: • VC encoded This is the format defined by the 1000 series. Connections to these switches are not supported in Fabric OS v4.0.0 and later. • native Introduced with the 2000 series, this format supports up to 16 ports per switch. • core The default for 4/16 SAN Switch and 4/8 SAN Switch, SAN Switch 2/8V, SAN Switch 2/16V, SAN Switch 2/32, SAN Switch 4/32, 4/64 SAN Switch, 400 MP Router, SAN Director 2/128, and 4/256 SAN Director. This is the recommended format for HP StorageWorks switches and fabrics. It uses the entire 8-bit address space and directly uses the port number as the area_ID. It supports up to 256 ports per switch. • extended edge This format generates the same PID for a port on switches with 16 ports or less as would native PID format, but it also supports up to 256 ports per domain. It should be used only in cases where you cannot upgrade devices to dynamic PID binding and you absolutely cannot reboot your servers. Extended edge PID is supported in Fabric OS v2.6.2 and later, v3.1.2 and later, and v4.2.0 and later. In addition to the PID formats list here, Interoperability mode supports additional PID formats that are not discussed in this guide. Fabric OS 5.3.0 administrator guide 423