Explanation
This is the best solution to increase the speed of the NIC because link aggregation is a technique that combines multiple physical network interfaces into asingle logical interface. This can increase the bandwidth, redundancy, and load balancing of network traffic. Link aggregation requires both the server and the switch to support it and be configured accordingly.References:https://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html

The bootloader configuration file is used to specify which kernel version and options to use when booting the system. The first kernel stanza in the file is the default one that is loaded automatically. By editing this stanza and changing it to point to the last known-good kernel files, the administrator can boot the system with a working kernel and avoid any compatibility issues with the new kernel update. Verified References: [How To Change The Linux Kernel Version]

This is the most likely reason why the fans in that server are operating at full speed while the ambient temperature in the room is normal and the other servers in the rack are not experiencing this behavior. A fan failure is a situation where one or more fans in a server stop working or malfunction due to wear and tear, dust, or other factors. This can cause overheating and performance issues on the server. To prevent this, most servers have a fan redundancy feature that allows the other fans to increase their speed and airflow to compensate for the failed fan and maintain a safe temperature level. The server is not likely to be in the process of shutting down, as this would not cause the fans to run at high speeds. An incorrect fan size is not likely to be inserted into the server, as most fans are standardized and compatible with the server chassis and motherboard. The server is not likely to be utilizing more memory than the other servers, as this would not cause a significant increase in temperature or fan speed. References:
https://www.howtogeek.com/303282/how-to-manage-your-pcs-fans-for-optimal-airflow-and-cooling/
https://www.howtogeek.com/174288/how-to-tell-if-your-computer-is-overheating-and-what-to-do-about-it/