Recently, the FCIA hosted a live webcast, “Data Center Scalability Made Easy with Fibre Channel Services” where our Fibre Channel experts, Barry Maskas of HPE, David Peterson of Broadcom and Kiran Ranabhor of Cisco provided context to the terminology and explanations on Fibre Channel Services, including device and topology discovery, zoning, security, clock synchronization and management. If you missed the live event you can watch it on-demand at BrightTALK or at the FCIA YouTube Channel.
We ran out of time during the live event to answer questions. Our experts have answered them here:
Q: Is there a limit to how large the Name Server can be?
A: There is no specified limit on the number of Name Server entries per Switch, however there are implementation limits. An important aspect of E_Port and Distributed Service Fabric scale is each Switch may have its’ own Name Server database size.
Q: Are Fabric services required, can they be turned off?
A: Fabric services are required for switched Fabrics for initiators and targets to operate properly in a Fibre Channel SAN, and are always on.
Q: Is the Distributed Name Server a potential single point of failure? Is there a backup?
A: Each Name Server can stand alone, or as a part of a Fabric. If there is a failure it is contained to the affected Switch.
Q: Can the Clock synchronization service be used in place of an NTP server?
A: No, conventional network technologies utilize clock distribution protocols (e.g., Network Time Protocol) that synchronize the computer’s time-of-day clock. Such protocols typically provide clock synchronization accuracies on the order tens of a milliseconds, with highly tuned versions producing accuracies on the order of one millisecond or less.
The Fibre Channel clock synchronization service allows clocks located within nodes to be synchronized to microsecond accuracies. If all sources of error are accounted for, then higher accuracies are possible.
Q: Must all N_Port_IDs be unique, what happens if a duplicate is discovered?
A: Yes, N_Port_IDs must be unique in a Fabric. A duplicate N_Port_ID is not possible because the Fabric Login service assigns the IDs.