# AI agents consume all your memory in linux by default > Source: > Published: 2026-09-19 00:10:27+00:00 My **64 GB Linux workstation** kept freezing while coding agents worked on a couple of projects. All 4 GB of swap filled up. Applications were killed. Half the memory looked like cache. Then I found **22 GB of agent-created files in a tmpfs-backed `/tmp`**. `tmpfs` stores file contents in **RAM or swap**. Unlike clean disk-backed cache, those contents cannot simply be discarded. Some memory monitors include tmpfs in cache-related accounting, making the memory pressure easy to misread.1 Memory-backed temporary storage can offer fast I/O, fewer storage writes, and cleanup on reboot. But swapping can undermine those benefits.2 The distinction is workload size. Systemd recommends `/tmp` for **small, bounded files** and `/var/tmp` for larger data.3 This is not uniquely an AI problem: GCC also creates temporary intermediate files.4 Parallel agent work simply made the trade-off visible on my machine. Run these in a Linux terminal: ``` # Filesystem containing /tmp findmnt -T /tmp -o TARGET,SOURCE,FSTYPE # Capacity and usage of that filesystem df -hT /tmp # Directory sizes, largest last; stay on one filesystem sudo du -x -h --max-depth=1 /tmp | sort -h # RAM and swap usage free -h ``` Look for `tmpfs` under `FSTYPE`. Keep `-T`: plain `findmnt /tmp` can return nothing when `/tmp` is not a separate mount.5 `df` measures the containing filesystem; `du` measures the directory tree.67 In `free`, focus on **` available`**.8 Large tmpfs usage alongside low available memory deserves investigation—not automatic blame for every crash. Create a private directory and check its filesystem and free space: ``` mkdir -p "$HOME/.local/tmp" chmod 700 "$HOME/.local/tmp" findmnt -T "$HOME/.local/tmp" -o TARGET,SOURCE,FSTYPE df -hT "$HOME/.local/tmp" ``` `mkdir -p` creates missing directories; `chmod 700` restricts ordinary access to the owner.910 Confirm the directory is disk-backed before proceeding. ``` export TMPDIR="$HOME/.local/tmp" ``` **Launch your agent from that same terminal.** Programs honoring `TMPDIR` can use the new location. Hard-coded `/tmp` paths and existing workspaces need separate changes.3 Verify the path and filesystem **inside the agent’s actual execution environment**, especially with containers or sandboxes.5 Clean up completed scratch data yourself; this directory does not inherit `/tmp`’s cleanup policy.3 `/tmp` disk-backed system-wide For systemd-based distributions, inspect first: ``` # Mount unit and any overrides systemctl cat tmp.mount --no-pager # Explicit /tmp configuration; no output means no matching entry findmnt --fstab --mountpoint /tmp # Root filesystem, mount options, and free space findmnt -T / -o TARGET,SOURCE,FSTYPE,OPTIONS df -hT / ``` `tmp.mount` is one name, with a dot.11 Use the following only when `/tmp` is tmpfs, its unit is distribution-provided with no local customizations, `/etc/fstab` has no `/tmp` entry, and `/` is writable, disk-backed, and has adequate space. Otherwise, use Option 1 rather than forcing this shortcut.511 ``` sudo systemctl mask tmp.mount ``` This prevents future activation without unmounting the current `/tmp`.11 **Save your work, copy anything needed out of `/tmp`, then reboot when ready. Existing tmpfs files disappear; they do not migrate to disk.**1 After reboot, verify: ``` findmnt -T /tmp -o TARGET,SOURCE,FSTYPE ``` `/tmp` should now belong to the disk-backed root filesystem. To reverse the mask, run `sudo systemctl unmask tmp.mount`, then reboot.11 This trades memory-backed storage for root-disk usage and can remove mount-specific restrictions such as `nosuid,nodev`. Disk space, cleanup, and security policy still matter.123 Native macOS and Windows normally use **disk-backed temporary directories**, so large temporary trees primarily consume disk space.1314 They can still exhaust memory; disk-backed does not mean cache-free.15 For Linux containers or virtual machines, check inside that environment.5 This is not a reason to disable tmpfs everywhere. It is a reason to put multi-gigabyte workspaces on storage chosen deliberately. **“Temporary” describes how long data is needed—not where it belongs.** [Linux kernel: Tmpfs](https://www.kernel.org/doc/html/latest/filesystems/tmpfs.html). ↩ [Ubuntu: Data Driven Analysis — /tmp on tmpfs](https://ubuntu.com/blog/data-driven-analysis-tmp-on-tmpfs). ↩ [systemd: Using /tmp/ and /var/tmp/ Safely](https://systemd.io/TEMPORARY_DIRECTORIES/). ↩ [GCC: Environment Variables](https://gcc.gnu.org/onlinedocs/gcc/Environment-Variables.html). ↩ [findmnt(8)](https://man7.org/linux/man-pages/man8/findmnt.8.html). ↩ [df(1)](https://man7.org/linux/man-pages/man1/df.1.html). ↩ [du(1)](https://man7.org/linux/man-pages/man1/du.1.html). ↩ [free(1)](https://man7.org/linux/man-pages/man1/free.1.html). ↩ [mkdir(1)](https://man7.org/linux/man-pages/man1/mkdir.1.html). ↩ [chmod(1)](https://man7.org/linux/man-pages/man1/chmod.1.html). ↩ [systemctl(1)](https://man7.org/linux/man-pages/man1/systemctl.1.html). ↩ [systemd: upstream tmp.mount](https://raw.githubusercontent.com/systemd/systemd/main/units/tmp.mount). ↩ [Apple: File System Basics](https://developer.apple.com/library/archive/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html). ↩ [Microsoft: GetTempPath2](https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-gettemppath2a). ↩ [Microsoft: File Caching](https://learn.microsoft.com/en-us/windows/win32/fileio/file-caching). ↩