Practical steps to mount tmpfs with the right options to balance speed and security. 16.11.2025 | reading time: 3 min Tmpfs is a RAM-backed filesystem that is fast but ephemeral; configure it deliberately to avoid surprises when performance or security matters. Mount tmpfs in one command Do it now: mount a RAM filesystem with explicit options to see effects immediately. ```bash sudo mount -t tmpfs -o size=512M,mode=1777,nosuid,nodev,noexec tmpfs /mnt/ram df -h /mnt/ram mount | grep /mnt/ram ``` Expected output example: ```bash Filesystem Size Used Avail Use% Mounted on tmpfs 512M 0 512M 0% /mnt/ram tmpfs on /mnt/ram type tmpfs (rw,nosuid,nodev,noexec,size=524288k,mode=01777) ``` Persist settings via fstab Make the choice survive reboot by adding a clear fstab entry and then test with mount -a. ```bash sudo sh -c 'echo "tmpfs /run/mytmp tmpfs rw,size=256M,mode=1777,nosuid,nodev 0 0" >> /etc/fstab' sudo mount -a mount | grep /run/mytmp ``` This creates a tmpfs at /run/mytmp with enforced size and security flags. Why each option matters Set size to limit RAM usage, use mode to control permissions, and add nosuid,nodev,noexec to reduce attack surface; tmpfs uses pages and can swap, so limits prevent memory exhaustion and nr_inodes controls inode density for many small files. When and where to use tmpfs Use tmpfs for /run, ephemeral caches, CI build workspaces, or any temporary data that benefits from RAM speed but must not survive reboot; avoid storing critical persistent data on tmpfs and pair tmpfs with systemd-tmpfiles or cron scripts when cleanup policies are needed. Tools that help manage tmpfs Use mount to create or remount filesystems, edit /etc/fstab for persistence, and inspect memory usage with df, free or /proc/meminfo to ensure tmpfs allocations are safe. Wrap-up and next steps Experiment with a small tmpfs first, observe memory and swap behavior, then apply tighter options on production mounts; broaden expertise by studying systemd tmpfiles, kernel memory management, and pursue certifications like CompTIA Linux+ or LPIC-1 with intensive exam preparation at bitsandbytes.academy to turn hands-on skill into a credential. Join Bits & Bytes Academy First class LINUX exam preparation. filesystem storage boot-process security
