server-stats.sh

Project for DevOps roadmap on roadmap.sh

https://roadmap.sh/projects/server-stats

System Usage Report Script

A Bash script that prints a quick snapshot of CPU, memory, and disk usage, along with the top 5 processes by CPU and memory consumption.

What it does

• CPU usage — overall current usage, calculated as 100% - idle%
• Memory usage — total / used / free (including cache/buffers as reclaimable), with percentage used
• Disk usage — total / used / available across all mounted filesystems, with percentage used
• Top 5 processes by CPU usage — PID, command, and CPU%
• Top 5 processes by memory usage — PID, command, and MEM%

All sections are computed from a single cached top -bn2 snapshot, so the script only pays the top sampling delay once.

Requirements

This script was built and tested on a standard Linux desktop/server setup and depends on the following:

Tool	Required version / notes
bash	Any modern version
top	procps-ng flavor (standard on Debian, Ubuntu, Fedora, RHEL/CentOS, Arch). BusyBox top (Alpine, minimal containers) is not supported — different output format.
free	procps-ng version with an available column (v3.3.10+, i.e. most systems from ~2014 onward)
df	Standard GNU coreutils df
awk	Any POSIX-compliant awk (gawk, mawk, BusyBox awk all work — no gawk-only features used)

Not guaranteed to work on

• Alpine Linux or other BusyBox-based systems (different top output format)
• Very old distros with legacy free (no available column)
• Minimal containers without bash installed

Usage

1. Clone the repository
2. Make it executable:

   chmod +x server-stats.sh

3. Run it:

   ./server-stats.sh

No arguments or flags — it just runs and prints the full report.

Example output

----------------------CPU usage:----------------------
Your current CPU usage is 4.3%
----------------------Memory usage:----------------------
You are using 47.03% of your memory
Total: 14.94Gi
Used: 7.04Gi
Free: 7.90Gi
----------------------Disk usage:----------------------
You are using 62.15% of your disk
Size: 512.00G
Used: 318.20G
Available: 193.80G
----------------------Top 5 processes by CPU usage:----------------------
   Usage  PID  Command
1. 9.1% 10998 Discord
2. 9.1% 57966 top
3. 0.0% 1 systemd
4. 0.0% 2 kthreadd
5. 0.0% 3 pool_wo+
----------------------Top 5 processes by memory usage:----------------------
   Usage  PID  Command
1. 5.6% 5388 brave
2. 3.5% 11367 Discord
3. 1.4% 10998 Discord
4. 0.1% 1 systemd
5. 0.0% 57966 top

Known limitations

• CPU snapshot accuracy: top -bn2 takes two samples ~3 seconds apart and uses the second (more accurate) one for the top-5 lists. The single-line "current CPU usage" figure is drawn from the same second sample.
• Colored/bold output uses ANSI escape codes — these render correctly in a normal terminal but will appear as raw escape characters if output is redirected to a file or a non-ANSI-aware destination (e.g. some log viewers, cron mail).

Troubleshooting

• Output looks wrong or empty: check your top flavor with top --version — it should say "procps-ng". If not, the script's column-position logic won't match your top's output format.
• Memory section errors out: check free -m — the header row should include an available column. If it doesn't, your free version is too old for this script as written.