Inspect RAM and swap quickly with the free command to spot memory bottlenecks in seconds. 16.11.2025 | reading time: 2 min Want a fast answer about system memory? Use the built-in `free` command to get a compact snapshot of RAM and swap usage, and decide if processes, cache or swap cause the slowdowns. Quick inspection: real session Run a single check and read the numbers: ``` $ free -h total used free shared buff/cache available Mem: 15Gi 6.2Gi 2.1Gi 256Mi 6.7Gi 8.3Gi Swap: 2.0Gi 0B 2.0Gi ``` See the available column for what processes can actually use and the buff/cache column for file cache reclaimed when needed. Read the columns Total is installed memory, used is what the kernel currently counts as used, free is genuinely unused, shared shows tmpfs and similar, buff/cache holds page cache and buffers, and available is the kernel's estimate of memory immediately available to start new apps. Options that matter A few flags change context: use `-h` for human-readable numbers, `-s` to sample periodically, `-t` to show a total line, and `--si` to use SI units; combine them to script checks and to gather time-series samples for analysis. When free is not enough If you need per-process detail or historical trends, reach for `top` or `htop` for interactive inspection, `vmstat` for lightweight stats, or perf and systemd-cgtop when resource control and profiling are required. Keep watching memory Memory behavior changes with workload; check `free` regularly during the scenario you troubleshoot and correlate with process lists or logs; learn more about LINUX internals and consider pursuing certifications such as CompTIA Linux+ or LPIC-1, and use bitsandbytes.academy for intensive exam preparation. Join Bits & Bytes Academy First class LINUX exam preparation. processes utilities troubleshooting
