.Part 5 Storage Security Best Practices and Support Information HP SAN Design Reference Guide 785355-001

Fabric segmentation errors
The following errors can cause fabric segmentation:
• Zone type mismatch
The name of a zone object in one fabric is identical to the name of a different type of zone
object in the other fabric. For example, an object name on fabric A must not be an alias or
configuration name in fabric B; otherwise, the fabrics cannot merge.
• Zone content mismatch
The definition of a zone object in one fabric is different from its definition in the other fabric.
If an alias, zone, or configuration name is the same on both fabric A and B, but the content
or definition of the objects is different, the fabrics cannot merge.
• Zone configuration mismatch
Zoning is enabled for both fabrics, but the zone configurations are different. The fabrics cannot
merge until the zone configuration is disabled for one of the fabrics.
• Duplicate IDs
Each switch in a fabric must have a unique domain ID; each switch in multiple fabrics of the
SAN must also have a unique ID. For example, if fabric A has five switches with domain IDs
1 through 5, and fabric B has five switches with the same domain IDs, these two fabrics cannot
merge until each switch in both fabrics has a unique domain ID.
For port-level zoning, changing the domain IDs can disrupt device access. Port-level zones
are based on the domain ID and port number.
Switch configuration parameters
Mismatched switch parameters can cause a SAN merger to fail. The configuration settings for all
switches in the fabric must match, with the exception of the following parameters:
• Switch name
• IP address
• Domain ID
Independent fabric merge
Merge fabrics by disabling the effective configuration on one fabric and then connecting both
fabrics. After you connect the fabrics, devices in the second fabric are not accessible until you add
them to the effective configuration.
CAUTION: When you disable the effective configuration, the fabric becomes accessible to all
servers.
To merge two fabrics without disabling the effective configuration for entire fabrics, disable at least
one switch in each fabric or use an additional switch. Use the disabled switch to merge the fabrics
and create the new configuration.
High-availability redundant fabric merge
With redundant fabrics, you can merge a fabric by taking it offline and redirecting I/O to the
other fabric. Current I/O operations are not affected; however, during the merge, the hosts operate
in degraded mode without redundant data path protection. With proper planning, you can minimize
downtime. After completing and verifying the fabric merge, bring the first fabric online by restoring
the I/O paths. After you restore the I/O paths on the first fabric, you can repeat the merge process
for the second fabric.
Merging high-availability fabrics example
SAN fabric merging 403