What happens if RAM is improperly sized in a Linux system?

When RAM is improperly sized in a Linux system, the most significant consequence is increased disk I/O due to swapping. When the physical RAM is insufficient to handle the workload, the operating system resorts to using swap space on the disk to compensate for the lack of available memory. This process involves moving inactive pages of memory to disk, which is significantly slower than accessing RAM.

As a result, the system experiences increased disk I/O activity because it has to frequently read from and write to the swap space, which can lead to performance degradation. Applications may become slower to respond, and overall system performance can be adversely affected as the processes compete for limited memory resources.

Improperly sized RAM can create a bottleneck because while swap space allows for additional memory, it is not a substitute for the speed and efficiency of physical RAM. In contrast, the other options provided do not directly correlate with the impacts of RAM sizing; for instance, file system errors are typically related to filesystem management issues rather than memory size, applications running faster is unlikely without adequate RAM, and network connectivity is not directly affected by RAM sizing.