HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

Fabric OS 6.1.x administrator guide 315
a router virtual domain that represents an entire fabric. Device connectivity can be achieved from one
fabric to another—over the backbone or edge fabric through this virtual domain—without merging the
two fabrics. Translate phantom domains are sometimes referred to as translate domains or xlate
domains.
If an FC router is attached to an edge fabric using an EX_Port, it will create translate phantom domains
in the fabric corresponding to the imported edge fabrics with active LSANs defined. If you import
devices into the backbone fabric, a translate phantom domain is created in the backbone device in
addition to the one in the edge fabric.
If you lose connectivity to the edge fabric due to link failures or disabling the IFL, translate phantom
domains remain visible. This prevents unnecessary fabric disruptions caused by translate phantom
domains repeatedly going offline and online due to corresponding IFL failures. To remove the translate
phantom domain from the backbone, disable all EX_Ports or VEX_Ports through which the translate
phantom domain was created.
Figure 39 shows another metaSAN consisting of a host in Edge SAN 1 connected to storage in Edge
SAN 2 through a backbone fabric connecting two 4/256 SAN Director, each containing an FR4-18i.
Figure 39 Edge SANs connected through a backbone fabric
Proxy devices
A 400 MP Router, 4/256 SAN Director or DC Director with an FR4-18i achieves interfabric device
connectivity by creating proxy devices (hosts and targets) in attached fabrics that represent real devices in
other fabrics. For example, a host in Fabric 1 can communicate with a target in Fabric 2 as follows:
• A proxy target in Fabric 1 represents the real target in Fabric 2.
• Likewise, a proxy host in Fabric 2 represents the real host in Fabric 1.
The host discovers and sends Fibre Channel frames to the proxy target. The 400 MP Router, 4/256 SAN
Director or DC Director with an FR4-18i receives these frames, translates them appropriately, and then
delivers them to the destination fabric for delivery to the target.
The target responds by sending frames to the proxy host. Hosts and targets are exported from the edge
SAN to which they are attached and, correspondingly, imported into the edge SAN reached through Fibre
Channel routing. Figure 40 illustrates this concept.
= LSAN
Edge SAN 2Edge SAN 1
Backbone
fabric
4/256 SAN Director
with
FR4-18i blade
4/256 SAN Director
with
FR4-18i blade
E_Port
E_Port
IFL IFL
EX_Port
EX_Port
ISL