{
  "id": "linux-storage-inspection",
  "title": "Find What's Actually Using the Disk",
  "category": "Linux Administration",
  "isolation_type": "shared_namespace",
  "difficulty": "Easy",
  "type": "task",
  "weight": 4,
  "description": "## Find What's Actually Using the Disk\n\nThree directories under `/srv/storage-lab/` (`logs`, `cache`, `data`) contain different amounts of data. \"It's probably the logs\" is a guess — find the real answer.\n\n**Your task:**\n\n1. Use `du` to measure the actual size of each of the three directories\n2. Use `df` to check overall filesystem usage on `/`\n3. Write the name of the directory (just `logs`, `cache`, or `data`) that uses the MOST space to `/srv/storage-lab/biggest.txt`",
  "hints": [
    {
      "title": "Measuring each directory",
      "body": "`du -sh <dir>` summarizes total size for one directory. Run it against all three, or use a wildcard to see them side by side.",
      "command": "du -sh /srv/storage-lab/*/"
    },
    {
      "title": "Overall filesystem usage",
      "body": "`df -h /` shows total/used/available space for the filesystem root lives on — a different, complementary question from `du` (which measures a specific directory's contents).",
      "command": "df -h /"
    }
  ],
  "setup_commands": [
    { "command": "mkdir -p /srv/storage-lab/logs /srv/storage-lab/cache /srv/storage-lab/data" },
    { "command": "dd if=/dev/zero of=/srv/storage-lab/logs/app.log bs=1M count=1 2>/dev/null" },
    { "command": "dd if=/dev/zero of=/srv/storage-lab/cache/blob.bin bs=1M count=10 2>/dev/null" },
    { "command": "dd if=/dev/zero of=/srv/storage-lab/data/small.txt bs=1K count=2 2>/dev/null" }
  ],
  "validation": {
    "commands": [
      { "description": "correctly identified cache/ as the largest consumer", "command": "cat /srv/storage-lab/biggest.txt", "expected_output": "cache", "match": "exact" }
    ]
  },
  "default_namespace": "default",
  "teardown_commands": [
    { "command": "rm -rf /srv/storage-lab" }
  ]
}