How to Quickly Inspect Server Hardware and OS Details on Linux

Introduction

When taking over one or more servers, understanding their basic configuration is essential for effective software deployment and system maintenance.

1. Operating System Information

Use the following commands to view OS version and kernel details: # cat /etc/redhat-release Displays the Red Hat‑based distribution version, e.g., CentOS Linux release 7.4.1708 (Core). # cat /etc/issue Works on most Linux distributions to show a brief OS description. # uname -r Shows the kernel version, e.g., 3.10.0-693.el7.x86_64. # uname -a Provides full kernel and system information, revealing hostname, architecture, and more.

2. CPU Details

Key terminology:

Physical CPUs : Number of CPU sockets installed.

CPU cores : Number of processing cores per socket.

Logical CPUs / Threads : Physical CPUs × cores, plus hyper‑threading if present.

Commands to retrieve CPU information:

# grep 'physical id' /proc/cpuinfo | sort -u | wc -l

Returns the count of physical CPUs.

# grep 'core id' /proc/cpuinfo | sort -u | wc -l

Shows the number of cores. # cat /proc/cpuinfo | grep processor | wc -l Displays the total logical CPU count (threads). # cat /proc/cpuinfo | grep name | sort | uniq Shows the CPU model, e.g., Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz. # lscpu Provides a concise summary of architecture, CPU(s), cores, threads, sockets, cache sizes, and flags.

3. Memory Information

Key terms:

Mem : Physical memory usage.

Swap : Virtual memory on disk.

Buffers and Cached : Memory used for I/O buffering and cached file data.

Command to view memory status: # free -m Outputs total, used, free, shared, buff/cache, and available memory in megabytes.

To monitor memory continuously every 3 seconds:

# free -s 3

4. Disk Usage

Overall disk usage: # df -h Shows filesystem size, used space, available space, and usage percentage in human‑readable format.

Directory‑specific usage: # du -sh /home/ Summarizes the total size of /home. Use -a, -h, --max-depth, etc., for more detailed reports.

Tree view of directory structure (requires tree package):

# yum -y install tree

# tree -L 2 /home/

5. Block Device Details

List block devices with sizes and mount points: # lsblk Provides columns for NAME, MAJ:MIN, RM, SIZE, RO, TYPE, and MOUNTPOINT.

Show UUIDs, filesystem types, and labels: # blkid Outputs each device’s UUID and TYPE, useful for identifying partitions.

Conclusion

By running these simple commands, you can quickly gather comprehensive information about a Linux server’s operating system, CPU, memory, storage, and block devices, enabling informed decisions for deployment, troubleshooting, and performance tuning.