How to Quickly Inspect Linux Server Hardware and OS Details with Simple Commands

1. Introduction

When taking over one or more servers, it is essential to understand their basic configuration to facilitate targeted troubleshooting and efficient software deployment.

2. Server Basic Configuration

Typical queries include the operating system, CPU, memory, and disk.

2.1 Operating System Information

Commands to view OS version and kernel:

# cat /etc/redhat-release
# cat /etc/issue
# uname -r
# uname -a
# more /etc/*release

2.2 CPU Information

Physical CPUs : number of CPUs physically installed on the motherboard.

CPU cores : number of processing cores per CPU (e.g., dual‑core, quad‑core).

Logical CPUs / threads : usually physical × cores; if greater, hyper‑threading is enabled.

Key commands:

# grep 'physical id' /proc/cpuinfo | sort -u | wc -l   # physical CPUs
# grep 'core id' /proc/cpuinfo | sort -u | wc -l       # core count
# cat /proc/cpuinfo | grep "processor" | wc -l         # logical CPUs
# cat /proc/cpuinfo | grep name | sort | uniq          # CPU model name
# dmidecode -s processor-version | uniq               # CPU model (alternative)
# cat /proc/cpuinfo                                    # detailed CPU info
# lscpu                                               # summarized CPU info

2.3 Memory Information

Mem : total physical memory.

Swap : virtual memory on disk.

shared : memory shared between processes.

buffers : memory used for block device I/O.

cached : memory used for cached file data.

total : total memory (used + free).

used : memory currently in use.

free : memory not used at all.

Commands to view memory status:

# free -m
# free -s 3

Linux treats cached and buffers as reclaimable, so they are considered usable memory in addition to the free column.

2.4 Disk Information

Commands to inspect disk usage and layout:

# df -h
# du -sh /home/
# du -ach --max-depth=2 /home/
# tree -L 2 /home/
# lsblk
# blkid

df -h

shows filesystem size, used and available space. du reports directory sizes, optionally with depth control. tree displays a hierarchical view of directories. lsblk lists block devices with size and mount points, while blkid reveals UUIDs, filesystem types, and labels.