HP StorageWorks SAN Virtualization Services Platform administrator guide (5697-0204, January 2010)

• Use zoning objects on the switch as zone members. Zoning objects allow you to create logical
representations on the switch of physical devices and ports in the SAN. These objects can be
modified or removed as the physical topology changes and are easier to manage.
• Follow a logical naming convention for zoning objects and zones that is readable and can be
understood by anyone with knowledge of the HP SVSP. For example, a zoning object name (for
example, VSM1_H1_5a14) could tell someone the device, the HBA on the device, and what port
number on the device, that the object represents. Similarly, a zone name could tell someone which
zoning objects are contained in the zone. Naming conventions are a personal preference but
should convey meaningful information about the zone and be easily understood. Tables 1 and 2
in the Zoning Components in HP SVSP section provide an example naming convention that can
be used with HP SVSP.
• Verify the zoning configuration afterwards. Devices being able to see each other and accessing
presented virtual disks or LUNs is no guarantee that the zoning configuration is correct with all
the expected paths between devices. Some zoning errors will not manifest themselves until certain
events, such as a path failover, occur. Using path failover tests within a fabric and across fabrics
should be a part of zone verification for HP SVSP.
• Use symmetric zoning rules, similar names, and so on, in both fabrics.
HP SVSP zoning principles
An HP SVSP zoning configuration is different from zoning implemented in other SANs that have
devices that are strictly categorized as target or initiator devices. In HP SVSP, the VSM and Data Path
Module (DPM) are unique devices that act as both targets and initiators.
An HP SVSP zoning configuration can logically be divided into front-end and back-end zones
depending on the interaction between the devices in the zone. The general rule is that any zone used
to access an HP SVSP virtual disk is a front-end zone while any zone containing a storage device or
dealing with the underlying storage I/O is a back-end zone. All HP SVSP zones should follow these
basic guidelines to ensure the most stable, manageable configuration possible:
• Each zone contains a target device and an initiator device. In the case of the DPM and VSM,
these devices can be classified as targets or initiators, depending on what device they are inter-
acting with in a given zone. For example, in a Host-DPM zone, the DPM is the target while the
host is the initiator. However in a DPM-Storage zone, the DPM is the initiator while the storage
device is the target.
• Each zone contains exactly two device types. For example, HP recommends you have two zones
for the DPM-VSM and Host-DPM rather than having a single zone containing the DPM, VSM, and
host devices.
• Each zone contains only two physical devices, where a target device can be represented by
multiple ports, but an initiator device can be represented by only a single port. For example, a
zone can contain four ports from a single storage device, but cannot contain two storage devices
with two ports each.
• Interaction between different zones must be taken into account if they share any devices. For ex-
ample, if two different hosts are accessing the same DPM front-end port through separate zones,
it is important to consider the possibility that the port might become a bottleneck in the configuration
if both hosts are accessing it simultaneously.
Using “super zones” with a large number of devices is highly discouraged with HP SVSP, since this
can lead to unpredictable communication between devices over the SAN and makes the zone
configuration harder to adjust in the future.
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