HP StorageWorks Fabric OS 5.2.x administrator guide (5697-0014, November 2009)

Fabric OS 5.2.x administrator guide 135
Admin domain compatibility and availability
Admin Domains maintain continuity of service for Fabric OS 5.2.x features and operate in mixed-release
fabric environments. High availability is supported along with some backward compatibility. The following
sections describe the continuity features of Admin Domain usage.
Admin domains and merging
When an E_Port comes online, the adjacent switches merge their AD databases. The receiving switch
accepts an AD database from the neighboring switch only if the local AD database is empty or if the new
AD database exactly matches both the defined and effective configurations of the local AD database. If the
AD database merge fails, the E_Port is segmented with “AD conflict” error code.
Compatibility
Admin Domains can be implemented in fabrics with mix of AD-aware switches and AD-unaware switches.
The following considerations apply:
• In mixed-fabric configurations, the legacy switches allow unfiltered access to the fabric and its devices;
hence, these legacy switches should be managed by the physical fabric administrator.
• You must zone all ports and devices from legacy switches in the AD0 root zone database.
• If you have legacy switches in your AD-activated fabric, you must ensure that all new AD resources have
enough interconnectivity so that they do not get isolated into subfabrics with a legacy subfabric
interposed in the middle, as shown in Figure 7.
Figure 7 Isolated subfabrics
Firmware upgrade and downgrade scenarios
You cannot perform a firmware downgrade from Fabric OS 5.2.x, if ADs are configured in the fabric.
Following are special scenarios for director class products only:
• If the primary and secondary CPs are running pre-Fabric OS 5.2.x and are in HA-Sync, if
firmwaredownload is used to upgrade one CP alone (using the firmwaredownload -s option),
then that CP will run in an AD-unaware mode (AD creation operations will fail and the local switch will
show up as an AD-unaware switch in the fabric).
• If the primary and secondary CPs are running Fabric OS 5.2.x and if ADs are configured, any attempt
to downgrade one or both CPs to pre Fabric OS 5.2.x versions will fail. The Admin Domain
configuration must be cleared before you can perform the downgrade (see ”Deleting all user-defined
Admin Domains” on page 142).
AD-aware fabric AD-aware fabricAD-unaware fabric
These two subfabrics have
different AD databases but
the same root zone database.