HP StorageWorks B-Series Remote Replication Solution Best Practices Guide (5697-6731, June 2007)

Figure 1 Simplest Meta SAN
Backbone fabric
The backbone fabric is the functional element that makes the logical connection between edge fabrics,
or bet ween the backbone fabric and an edge fabric. The backbone fabric, at a minimum consists, of
at least one MP Router, but can contain more than one M P Router and standard FC switches in the
backbone fabric. MP routers and F C switches in the backbone fabric are linked via a standard ISL
that is no different from any other FC fabric. The key factor that distinguishes the backbone fabric
is its connection to the edge fabrics.
This connection b et ween the backbone fabric a nd the edge fabric(s) is via an Inter-Fabric Link (IFL). The
backbone fabric side of the link is configured as an EX_Port while the edge fabric side of the link is
configured as an E_Port. This EX_Port is a version of the E_Port, and to the edge fabric, it appears like an
ordinary connection to any other FC switch. The main difference between an E_Port and a n EX_Por t is
that the EX_Port makes the backbone fabric appear to be a single FC switch to the edge fabric, regardless
of the number of MP Routers and FC switches that are in the backbone fabric.
The EX_Port is always the boundary point between the backbone fabric and an edge fabric a n d is in
theory part of the edge fabric. Figure 1 shows that the edge fabric includes all the FC switches and the
IFL up to and including the EX_Port of the backbone fabric.
With the 400 MP Router and the MP Router Blade, a limited number of hosts and/or storage devices
may be connected to the backbone fabric. These devices can be routed to the edge fabrics. Host and
storage devices connected to the backbone fabric that contains a 2 Gb MP Router are not routable to
any edge fabric.
LS AN zoning
LSAN zoning is the methodology that allows a subset of devices from separate fabrics to communicate.
An LSAN zone looks like any other zone in a fabric, with the exception that the zone name must begin
with LSAN_ (case insensitive). Day-to-day administration of LSAN zones is per formed using the zoning
tools within each fabric. This allows existing tools to work as usual, and minimizes the need to retrain
SAN administrators. If this specially named LSAN zone is created on two or more fabrics to which an MP
Rou
ter has access to, the MP Router will automatically create the Logical Storage Area N etworks (LSANs)
be
tween those fabrics. If a n LSAN spans two fabrics, there are two LSA N zones that define it—one on
each fabric. An LSAN that spans three fabrics would have three LSAN zones, and so on.
ThenameoftheLSANzoneintheseparatefabricsdoesnotneedtobethesame,buttheWWNofthe
de
vicesfrom‘local’and‘remote’fabricsmustbeinanLSANzoneinbothfabrics.
TIP:
WhileLSANzonesarenotrequiredtousethesamename,itisrecommendedthatyouusethesameor
similar names to aid in troubleshooting.
LSAN zoning only supports WW N zoning, as Port Identifiers (PID) are not unique in the fabric a nd, in
fact, two devices with exactly the same PID in t wo d ifferent fabrics can communicate via an LSAN zone.
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Solution setup overview