refactor(disk-check): use percentage-based disk space validation

- Changed from static 1GB minimum to percentage-based check
- Default: 10% of total disk must be free (scales with disk size)
- Configurable via RUNPOD_MIN_DISK_PERCENT environment variable
- Benefits:
  - Small disks (50GB): ~5GB free required
  - Large disks (1TB): ~100GB free required
- Automatically scales to machine resources
- Updated tests to verify percentage-based logic

Author: deanq

runpod/serverless/modules/rp_system_fitness.py

@@ -26,7 +26,7 @@
 
 # Configuration via environment variables
 MIN_MEMORY_GB = float(os.environ.get("RUNPOD_MIN_MEMORY_GB", "4.0"))
-MIN_DISK_GB = float(os.environ.get("RUNPOD_MIN_DISK_GB", "1.0"))
+MIN_DISK_PERCENT = float(os.environ.get("RUNPOD_MIN_DISK_PERCENT", "10.0"))
 MIN_CUDA_VERSION = os.environ.get("RUNPOD_MIN_CUDA_VERSION", "11.8")
 NETWORK_CHECK_TIMEOUT = int(os.environ.get("RUNPOD_NETWORK_CHECK_TIMEOUT", "5"))
 GPU_BENCHMARK_TIMEOUT = int(os.environ.get("RUNPOD_GPU_BENCHMARK_TIMEOUT", "2"))
@@ -123,6 +123,8 @@ def _check_disk_space() -> None:
     """
     Check disk space availability on root and /tmp.
 
+    Requires free space to be at least MIN_DISK_PERCENT% of total disk size.
+
     Raises:
         RuntimeError: If insufficient disk space
     """
@@ -134,16 +136,18 @@ def _check_disk_space() -> None:
             total_gb = usage.total / (1024**3)
             free_gb = usage.free / (1024**3)
             used_percent = 100 * (1 - free_gb / total_gb)
+            free_percent = 100 * (free_gb / total_gb)
 
-            if free_gb < MIN_DISK_GB:
+            # Check if free space is below the required percentage
+            if free_percent < MIN_DISK_PERCENT:
                 raise RuntimeError(
-                    f"Insufficient disk space on {path}: {free_gb:.2f}GB free, "
-                    f"{MIN_DISK_GB}GB required"
+                    f"Insufficient disk space on {path}: {free_gb:.2f}GB free "
+                    f"({free_percent:.1f}%), {MIN_DISK_PERCENT}% required"
                 )
 
-            log.debug(
+            log.info(
                 f"Disk space check passed on {path}: {free_gb:.2f}GB free "
-                f"({used_percent:.1f}% used)"
+                f"({free_percent:.1f}% available)"
             )
         except FileNotFoundError:
             # /tmp may not exist on some systems

tests/test_serverless/test_modules/test_system_fitness.py

@@ -97,35 +97,38 @@ def test_memory_info_works(self):
 class TestDiskSpaceCheck:
     """Tests for disk space checking."""
 
-    @patch("runpod.serverless.modules.rp_system_fitness.MIN_DISK_GB", 10.0)
+    @patch("runpod.serverless.modules.rp_system_fitness.MIN_DISK_PERCENT", 10.0)
     @patch("shutil.disk_usage")
     def test_sufficient_disk_passes(self, mock_disk_usage):
         """Test that sufficient disk space passes the check."""
         mock_usage = MagicMock()
+        # 100GB total, 50GB free (50% free) - should pass with 10% minimum
         mock_usage.total = 100 * 1024**3
         mock_usage.free = 50 * 1024**3
         mock_disk_usage.return_value = mock_usage
 
         # Should not raise
         _check_disk_space()
 
-    @patch("runpod.serverless.modules.rp_system_fitness.MIN_DISK_GB", 10.0)
+    @patch("runpod.serverless.modules.rp_system_fitness.MIN_DISK_PERCENT", 10.0)
     @patch("shutil.disk_usage")
     def test_insufficient_disk_fails(self, mock_disk_usage):
         """Test that insufficient disk space fails the check."""
         mock_usage = MagicMock()
-        mock_usage.total = 20 * 1024**3
+        # 100GB total, 5GB free (5% free) - should fail with 10% minimum
+        mock_usage.total = 100 * 1024**3
         mock_usage.free = 5 * 1024**3
         mock_disk_usage.return_value = mock_usage
 
         with pytest.raises(RuntimeError, match="Insufficient disk space"):
             _check_disk_space()
 
-    @patch("runpod.serverless.modules.rp_system_fitness.MIN_DISK_GB", 10.0)
+    @patch("runpod.serverless.modules.rp_system_fitness.MIN_DISK_PERCENT", 10.0)
     @patch("shutil.disk_usage")
     def test_checks_both_root_and_tmp(self, mock_disk_usage):
         """Test that both root and /tmp are checked."""
         mock_usage = MagicMock()
+        # 100GB total, 50GB free (50% free) - should pass
         mock_usage.total = 100 * 1024**3
         mock_usage.free = 50 * 1024**3
         mock_disk_usage.return_value = mock_usage