system-information.md

System information

Basic user enumeration

• whoami hostname - get username and hostname
• id - get information which group ids current user belongs to
• groups $USER - check groups
• last - check users that logged in recently

Cpu, memory

• lscpu - show cpu information
• free -h - display memory usage
• uname -p or uname -m - show system architecture
• uname -r - see a running kernel
• lsb_release -a or cat /etc/*release - see running distribution

Another useful tool sysstat package

• iostat - show current io (disk usage, cpu usage)
• mpstat - show current cpu usage (detailed)

Simple script to log system resources:

#!/bin/bash

set -eux

LOGFILE="/var/log/system_stats.log"

echo "Logging CPU, Memory, Swap, Disk, and Network usage to $LOGFILE"

while true; do
    echo "----- $(date) -----" >> $LOGFILE
    echo "CPU Usage:" >> $LOGFILE
    mpstat -P ALL 1 1 >> $LOGFILE

    echo "Disk Usage:" >> $LOGFILE
    iostat >> $LOGFILE

    echo "Memory and Swap Usage:" >> $LOGFILE
    free -m >> $LOGFILE

    echo "Network Usage:" >> $LOGFILE
    ifstat 1 1 >> $LOGFILE

    sleep 10
done