Technical data
DATA CENTER TECHNICAL BRIEF
Operational Simplicity: Automating and Simplifying SAN Provisioning 13 of 15
VerifyingDisruptiveLinks
After a SAN has been deployed into production, during the operational life cycle of the fabric, links may begin to
exhibit CRC errors or increased latency due to miscongurations or other problems (see Figure 5). The relevant
ports can be taken ofine (red link) and put into ClearLink D_Port mode without disrupting the fabric, if there are
additional connections between the switches to route trafc.
fig05_test-link
Fabric A Fabric B
Existing Links or Trunk
Disruptive Link
Figure 8. Testing a disruptive link.
The automated ClearLink D_Port tests can be used to verify if the problem is a cable issue or an optics issue.
Then the problem can be serviced accordingly, to minimize downtime.
VerifyingIntegrityofNewLink
As more switches and adapters are added to the fabric, or as additional ISLs are required for reducing
congestion, it is good practice to verify the integrity of the new connections. Prior to connecting the new link, the
two end ports can be placed in ClearLink D_Port mode and run through the diagnostic tests without disrupting
the existing fabric. Once the tests are completed and the integrity of the link is conrmed, the two end ports can
be connected to form an additional ISL or a trunk member without disrupting the trafc on an existing trunk.
ServerMigrationorReplacement
When servers come off lease, HBAs are replaced due to failure or are upgraded to handle increased workloads.
The SAN administrator needs to manually update the zone database to reect these changes. If DFP was used
during the pre-deployment stage, the SAN administrator does not have to interact with server administrators to
make any changes. For example (see Figure 6), if you need a new server that requires more CPU and memory,
and the existing server is repurposed, all that you need to do is to move the fabric-assigned WWN from one port
to another without changing the zone database.