> ## Documentation Index
> Fetch the complete documentation index at: https://docs.allthingslinux.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Resource Limits

> Disk quotas, CPU and memory limits, and process isolation on atl.sh.

atl.sh enforces per-user resource limits to keep the server fair and stable for everyone. Here's what applies to your account.

## Disk Quota

| Limit      | Value |
| ---------- | ----- |
| Soft limit | 5 GB  |
| Hard limit | 6 GB  |

The soft limit triggers a grace period warning. The hard limit is absolute — writes fail once you hit it.

Check your current usage:

```bash theme={null}
quota -s          # your disk usage and limits
du -sh ~          # total home directory size
du -sh ~/*/       # breakdown by subdirectory
ncdu ~            # interactive disk usage browser
```

Things that eat disk quickly: language package caches, build artifacts, log files. Keep `node_modules/`, `target/`, `.cache/`, and similar directories in check.

## CPU Limit

| Limit   | Value          |
| ------- | -------------- |
| Max CPU | 200% (2 cores) |

Enforced via systemd cgroup v2 per-user slice. Long-running CPU-intensive processes are fine — just be considerate of other users.

## Memory Limit

| Limit   | Value  |
| ------- | ------ |
| Max RAM | 1.5 GB |

Enforced via systemd cgroup v2. If your processes exceed this, the kernel OOM-kills them.

## Process Limits

| Limit                           | Value |
| ------------------------------- | ----- |
| Max tasks (processes + threads) | 200   |

Set via both PAM (`nproc`) and systemd cgroup.

## /tmp Isolation

Your `/tmp`, `/var/tmp`, and `/run/lock` are **private to your session** via `pam_namespace`. Other users cannot see or access files you create there. This is per-login — a new SSH session gets a fresh namespace.

This means:

* `/tmp/myfile` from your session is invisible to other users
* Shared IPC via `/tmp` across users won't work (use sockets in your home directory instead)

## Persistent Sessions with tmux

SSH sessions end when you disconnect. Use `tmux` to keep processes running:

```bash theme={null}
tmux              # start a new session
# ... start your process ...
# Ctrl-a d        detach (process keeps running)

tmux attach       # reattach later
tmux ls           # list running sessions
```

Long-running jobs like servers, builds, or downloads should always run inside tmux.

## Process Accounting

The server runs `acct` (process accounting), which records every command executed by every user. Admins can review this with `lastcomm` and `sa`. This is a standard pubnix practice — be aware that your command history is logged at the system level.

## Checking Resource Usage

```bash theme={null}
# Your current processes
ps aux --user $USER

# Memory and CPU usage
htop              # filter by user with 'u'
btop

# Per-process network usage
nethogs

# Disk I/O
iotop

# Bandwidth
vnstat            # historical bandwidth stats
```