"电子科技大学计算机系统结构课：磁盘故障率与频率问题"

In the field of computer system architecture, performance, cost, reliability, and power consumption are crucial factors that need to be considered. When it comes to coping with failures in a large-scale system, such as the scenario of having 4 disks per server in a network of 50,000 servers, the failure rate of disks becomes a critical concern. In this particular exercise, the failure rate of disks is assumed to be 4% annually. With this information, the question arises of how often a disk will fail on average. Given that there are 50,000 servers and each server has 4 disks, the total number of disks in the system is 200,000 (50,000 x 4). To calculate the average frequency of disk failures, we can multiply the total number of disks by the annual failure rate of 4%. This results in 8,000 disks failing every year (200,000 * 0.04). From this, we can determine the average frequency of disk failures by dividing the total number of failures by the total number of disks. This equates to 0.04 failures per disk annually (8,000 / 200,000). By converting this annual rate to a more easily understandable timeframe, we can calculate that, on average, a disk in the system will fail every 25 hours (1 / 0.04). This means that there will be approximately one disk failure every day in the network (24 hours x 1 / 25 hours). Therefore, based on the given parameters and calculations, the expected frequency of disk failures in a network with 4 disks per server and 50,000 servers is approximately one disk failure per day. This highlights the importance of implementing robust failure recovery mechanisms and redundancy strategies in large-scale computer systems to ensure uninterrupted operation and data integrity.