Exam SK0-005 topic 1 question 363 discussion

The key detail is that there are no link lights on both the SAN switch and the HBA. This indicates a physical layer problem, which is most commonly caused by cabling issues.

The answer is A because this is a physical layer problem, and using the wrong type of fiber optic cable can result in no connectivity, which would explain why there are no link lights on both the switch and HBA.

The most likely issue that prevents the newly added server from seeing any of the LUNs on the SAN is that a single-mode fiber cable is used in place of multimode. A single-mode fiber cable is a type of optical fiber cable that has a small core diameter and allows only one mode of light to propagate through it. A single-mode fiber cable can transmit data over long distances at high speeds, but it requires more expensive transceivers and connectors than multimode fiber cables. A multimode fiber cable is a type of optical fiber cable that has a larger core diameter and allows multiple modes of light to propagate through it. A multimode fiber cable can transmit data over short distances at lower speeds than single-mode fiber cables, but it is more compatible and cost-effective than single-mode fiber cables. If a single-mode fiber cable is used in place of multimode, it can cause signal loss, attenuation, or mismatch between the devices.

D. The zoning on the fiber switch is wrong. In a Storage Area Network (SAN) environment, zoning is a method of partitioning or segmenting the SAN fabric to control access to specific devices or resources such as LUNs. If the newly added server cannot see any of the LUNs on the SAN and both the SAN switch and the local HBA do not display any link lights, it suggests that there might be an issue with the zoning configuration. Zoning needs to be properly configured to allow communication between the server's HBA and the LUNs on the SAN. If the zoning is incorrect, the server will not be able to access the LUNs, resulting in the observed behavior.

D. The zoning on the fiber switch is wrong. If the SAN switch and the local HBA do not display any link lights, it indicates a physical connectivity problem between the server and the SAN. Zoning on the fiber switch is a common cause of such issues. Zoning determines which devices can communicate with each other over the Fibre Channel fabric. If the zoning is incorrect, the server may not be able to establish a connection with the SAN and access the LUNs. Therefore, checking and correcting the zoning configuration on the fiber switch would likely resolve the issue.