HI There
According to our team, looks like a problem with FC pigtail or (less likely) the transceiver on the server HBA. Check/replace the LC fiber cable between the corresponding ports. (!) Mind the bend radius constraints.
The fiber’s radius around bends impacts the fiber network’s long-term reliability and performance. Simply put, fibers bent beyond the specified minimum bend diameters can break, causing service failures and increasing network operations costs. Cable manufacturers, Internet and telecommunications service providers, and others
specify a minimum bend radius for fibers and fiber cables. The minimum bend radius will vary depending on the specific fiber cable.
However, in general, the minimum bend radius should not be less than ten times the outer diameter (OD) of the fiber cable. Thus a 3 mm cable should not have any bends less than 30mm in radius. The general recommendation is a minimum 38 mm bend radius for 3 mm patch cords (Generic Requirements and Design Considerations for Fiber Distributing Frames, GR-449-CORE, Issue 1, March 1995,
Section 3.8.14.4). This radius is for a fiber cable that is not under any load or tension. If a tensile load is applied to the cable, as in the weight of a cable in a long vertical run or a cable that is pulled tightly between two points, the minimum bend radius is increased, due to the added stress.
There are two reasons for maintaining minimum bend radius protection: enhancing the fiber’s long-term reliability and reducing signal attenuation. Bends with less than the specified minimum radius will exhibit a higher probability of long-term failure as the amount of stress put on the fiber grows. As the bend radius becomes even
smaller, the stress and probability of failure increase. The other effect of minimum bend radius violations is more immediate; the amount of attenuation through a bend in a fiber increases as the radius of the bend decreases. The attenuation due to bending is greater at 1550 nm than it is at 1310 nm—and even greater at 1625 nm. An attenuation level of up to 0.5 dB can be seen in a bend with a radius of 16 mm. Both fiber breakage and added attenuation have dramatic effects on long-term network reliability and network operations costs.
Kind regards,
Ask Fujitsu - Forum team