ProblemHow to change a Brocade switch to be the new principal switch
A switch by default is the principal because it happened to have the lower wwn at the time of introducing the switches into a fabric. The Hardware, Software Compatibility List (HSCL) dictates that (for a Brocade in this example) the minimum version of firmware for Proxy (principal) switch is 5.3.1a. 6.x. Always pick the highest version of firmware in the Fabric for the proxy switch. So, you may have the scenario where switches were introduced into a fabric but the lowest WWW happened to have the lowest firmware compared to another switch with a higher WWW and higher firmware.
You may want another switch to be the principal. One can use the Brocade command called: fabricprincipal (if supported in the current firmware) or see below:
From the HELP option on CCS GUI searching for 'principal switch':
When CommandCentral Storage discovers switches in a fabric, it considers the switch with the lowest World Wide Name (WWN) to be the principal switch. Then, by default, it assigns the fabric the same name as its principal switch.
If the principal switch is removed from the fabric, CommandCentral Storage will designate a new principal switch - again, the switch with the lowest WWN - when it discovers the fabric again. The name of the fabric will change as a result. For this reason, you may want to assign names manually to a fabric by editing its Display Name attribute.
Because all switches in the fabric share information such as zoning tables, a change in principal switch role does not cause a loss of information. The Zoning explorer, for example, periodically rescans the fabric and updates zoning information based on the zone information it discovers for all of the switches in the fabric.
Also, from: http://support.veritas.com/docs/261511
One way to change the 'principal' switch of a fabric is to reboot the 'principal' switch. When the 'principal' switch has been rebooted or removed, one of the 'subordinate' switches will assume the role of the 'principal' switch.
All switches in the fabric share information such as zoning tables and a reassignment of 'principal' switch role does not cause a loss of information. The zone explorer, for example, periodically rescans the fabric and updates zoning information based on reading the zone information from all of the switches in the fabric.