McDATA StorageWorks 2/140 - Director Switch Planning Manual page 148

Implementing SAN Internetworking Solutions
4
Zone FlexPars
McDATA Products in a SAN Environment - Planning Manual
4-6
• Create up to three additional FlexPars and assign resources to
those FlexPars.
• Perform director firmware upgrades to all Flexpars.
• Enable or disable the protocol subsystem for any Flexpar.
• Enable or disable switch modules and control processor (CTP)
cards.
• Perform director shutdowns, restarts, and field-replaceable unit
(FRU) switchovers.
• Set the director Internet protocol (IP) address, gateway address,
and subnet mask.
• Set the director date and time.
NOTE: An Intrepid 10000 Director set to fibre connection (FICON)
management style can have only one Flexpar (0) enabled.
Flexpar functionality aggregates small (32 port or less) and medium
(up to 256 port) SAN islands to a single point of control. Director
FlexPars are not intended to enable creation of larger fabrics.
Regardless of the number of Flexpars enabled, the maximum total
fabric size (summing all Flexpars) is limited to the maximum
configuration supported by the Director. Similarly, limits for other
fabric scalability elements (such as number of zones per zoneset) may
not exceed the maximum supported by a single fabric.
Because zoning is managed on a fabric wide basis, all directors and
fabric switches in a zone must maintain consistent zoning
information. To ensure consistency, registered state change
notifications (RSCNs) are transmitted to all attached devices when a
zoning change occurs, when a device is set offline or online, or when
a local switch is connected to or disconnected from the fabric.
When a device becomes available or unavailable, an RSCN is
transmitted only to devices in the same zone. However, a zoning
change causes an RSCN to be transmitted to all the devices in the
fabric. As fabrics grow larger, numerous RSCNs from zoning changes
can create congestion and disrupt devices, causing a pause in normal
activity to determine status of the other devices. In fact, many legacy
host bus adapters (HBAs) cease operation as they query the fabric
name server upon receipt of an RSCN.