A systems administrator notices a newly added server cannot see any of the LUNs on the SAN. The SAN switch and the local HBA do not display any link lights. Which of the following is most likely the issue?
正解:A
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. References: [CompTIA Server+ Certification Exam Objectives], Domain 3.0: Storage, Objective 3.2: Given a scenario, compare and contrast various storage technologies.