Quickly find, read and tweak the kernel's vm.* tuning knobs to improve memory handling and stability. 03.02.2026 | reading time: 2 min Many performance and stability issues start in the kernel's VM layer; checking vm parameters tells the story fast and gives levers to act on. Quick audit example In a terminal run `sysctl -a | grep "^vm\."` to list the VM tunables; example output and quick checks are shown below. ```bash $ sysctl vm.swappiness vm.swappiness = 60 $ sysctl -a | grep "^vm\." | head -n 8 vm.swappiness = 60 vm.overcommit_memory = 0 vm.overcommit_ratio = 50 vm.dirty_ratio = 20 vm.dirty_background_ratio = 10 vm.vfs_cache_pressure = 100 vm.min_free_kbytes = 67584 ``` Tweak now, persist safely Change a value immediately with `sudo sysctl -w vm.swappiness=10` to lower swapping, and make it persistent by creating `/etc/sysctl.d/99-custom.conf` with a line `vm.swappiness=10` and then run `sudo sysctl --system` to apply all files. Parameters that matter most Watch `vm.swappiness`, `vm.overcommit_memory`, `vm.overcommit_ratio`, `vm.dirty_ratio`, `vm.dirty_background_ratio`, `vm.vfs_cache_pressure` and `vm.min_free_kbytes` because they strongly influence swap behavior, memory overcommitment, writeback and cache retention. Related tools you will use Use `sysctl` for reads and writes, inspect `/proc/sys/vm/*` files directly for scripts, and consider `tuned-adm` or distribution tuning profiles for consistent system-wide settings. Next steps and learning Start by auditing vm settings on several systems, adjust one parameter at a time and observe behavior under load; to deepen skills consider studying for CompTIA Linux+ or LPIC-1 and try the intensive exam prep at bitsandbytes.academy. Join Bits & Bytes Academy First class LINUX exam preparation. virtualization processes utilities troubleshooting infrastructure
