Knowledge

5 Commands to Check Linux VPS Status: Load, RAM Usage, and Network

14
May

When using a VPS (Virtual Private Server) for hosting websites, running applications, or providing other services, it is crucial to ensure your server operates smoothly, does not overload, does not use all of its RAM, and maintains a stable network connection. In this article, VisperHost will guide you through 5 essential commands for checking system status on a Linux VPS that you need to know!

1. top: Check Load and real-time resource usage

The top command is one of the most essential tools for Linux administrators to monitor system performance in real time. It updates information every few seconds (the default is 3 seconds) , allowing you to instantly view CPU usage , RAM, swap, and active processes.

Basic Usage

Top

When you enter this command, the information will appear in a table divided into the following sections:

Line 1: General System Information

top - 14:05:23 up 1 day,  4:12,  1 user,  load average: 0.35, 0.42, 0.38
  • 14:05:23: Current system time
  • 1 day, 4:12: The system has been running for 1 day, 4 hours, 12 minutes (Uptime) .
  • 1 user: Number of users currently logged in
  • Load average: 0.35, 0.42, 0.38:
    • Average Load in the last 1, 5, and 15 minutes
    • This value should be closer to 1 (for 1 core) or closer to the number of CPU cores for better performance.
    • If the VPS has 2 cores → The value should not exceed 2.00

Line 2: Information about the Task (process)

Tasks: 114 total,  1 running, 113 sleeping, 0 stopped, 0 zombie
  • 114 total: Total number of processes
  • 1 running: The number of processes currently running.
  • 113 sleeping: A process that is in an idle state, waiting.
  • zombie: A process that has terminated but has not yet been removed (should be 0).

Lines 3–5: CPU Usage

%CPU(s): 5.0 us, 1.2 sy, 0.0 ni, 92.8 id, 0.0 wa, 0.0 hi, 1.0 si, 0.0 st
  • us (user): CPU usage by general processes
  • sy (system): Usage by system/kernel
  • id (idle): CPU is idle
  • wa (I/O wait): The CPU is waiting to read or write data from the disk.
  • st (steal): CPU is being used by the hypervisor (found in some VPS/cloud services).

Line 6–7: Memory (Memory / RAM / Swap)

MiB Mem:  1998.2 total,   980.5 free,   620.4 used,   397.3 buff/cache 
MiB Swap: 1024.0 total,  1024.0 free,     0.0 used.  1230.5 avail Mem
  • Total: Total memory
  • Used: Currently in use
  • Free: Available
  • buff/cache: Reserved for temporary use by the system (the system will reclaim if needed)

Key point: Look at avail Mem → This is the remaining RAM available for new processes.

Lower section: Process list

Example:

PID USER     PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND 
1234 root     20   0 500,000 12,000 3,000 S 5.3 0.6 0:12.34 apache2

Description:

  • PID: Process number
  • USER: Process owner
  • PR: Priority of process
  • %CPU: Percentage of CPU usage
  • COMMAND: process name

Press P to sort by CPU, M to sort by RAM

2. free -m: Check RAM and Swap usage

The free command is used to check the usage of memory (RAM) and swap space, which helps you determine if your VPS is nearing capacity.

free -m
  • -m displays results in MB units.
  • Check the used, free, and available lines to decide whether you should add RAM or improve your applications.

Result Description

Example of the command’s output:

             Total Used Free Shared Buff/Cache Available 
Mem: 1998 978 300         100 720 1200 
Swap: 1024 50 974

What does each column represent?

  • Total: The total amount of memory that the system has.
  • Used: The amount already in use by the system (including buffers/cache)
  • free: Memory that is still available
  • shared: The portion allocated for use by multiple processes.
  • buff/cache: Memory reserved by the system for performance
  • Available: Memory that is actually ready for use by a new process.

3. Uptime: Quick check of Load Average status

If you just want to quickly check the Load Average, the uptime command is a fast option.

uptime

Displays the duration the system has been running, along with the latest 1-minute, 5-minute, and 15-minute Load Average values, which help indicate whether the system is overloaded.

4. vnstat: Check Bandwidth Usage

If you want to see how much internet data your VPS uses each day, month, or during a specific period, the vnstat command is very suitable.

vnstat

If not yet installed, you can install it with:

sudo apt install vnstat

Display information such as:

  • Upload/Download Data Volume
  • Usage can be viewed by day, month, or in real-time (use vnstat -l )

5. netstat -tuln or ss -tuln: Check the status of network connections.

This command helps you determine which services are running and which ports they are listening on your VPS.

netstat -tuln
# หรือ
ss -tuln
  • t = TCP
  • u = UDP
  • l = Listening (Currently accepting connections)
  • n = Display the port number instead of the service name

This command helps analyze active ports and can also be used to control access for security purposes.

Summary:

Regular maintenance of your Linux VPS helps ensure system stability, prevents potential issues, and allows for efficient system expansion planning. Don’t forget to save these commands for future use:

  • Top
  • free -m
  • Uptime
  • vnstat
  • netstat -tuln or ss -tuln

If you’re looking for high-quality VPS with professional support, don’t forget to consider VisperHost.net, the VPS provider that understands Thai people the most!