In the realm of system administration and monitoring, understanding memory usage trends is crucial for maintaining system health and performance. While tools like htop offer real-time insights into memory usage, they lack the capability to provide historical data. So, what if you need to analyze memory usage over the past 24 hours or even a week? Fear not, as Sysstat comes to the rescue with its powerful sar command.   Installing Sysstat Before delving into historical memory usage...