Give warning if runpath disk space is close to full on ert startup

src/ert/config/model_config.py

@@ -1,13 +1,18 @@
 from __future__ import annotations
 
+import contextlib
 import logging
 import os.path
+import shutil
 from datetime import datetime
+from pathlib import Path
 from typing import no_type_check
 
 from pydantic import field_validator
 from pydantic.dataclasses import dataclass
 
+from ert.shared.status.utils import byte_with_unit
+
 from .parsing import (
     ConfigDict,
     ConfigKeys,
@@ -43,6 +48,11 @@ def str_to_datetime(date_str: str) -> datetime:
 DEFAULT_JOBNAME_FORMAT = "<CONFIG_FILE>-<IENS>"
 DEFAULT_ECLBASE_FORMAT = "ECLBASE<IENS>"
 
+FULL_DISK_PERCENTAGE_THRESHOLD = 0.97
+MINIMUM_BYTES_LEFT_ON_DISK_THRESHOLD = 200 * 1000**3  # 200 GB
+# We give warning if free disk space is less than MINIMUM_BYTES_LEFT_ON_DISK_THRESHOLD
+# and used space in percentage is greater than FULL_DISK_PERCENTAGE_THRESHOLD
+
 
 @dataclass
 class ModelConfig:
@@ -83,6 +93,19 @@ def validate_runpath(cls, runpath_format_string: str) -> str:
             )
             ConfigWarning.warn(msg)
             logger.warning(msg)
+        with contextlib.suppress(Exception):
+            mount_dir = _get_mount_directory(runpath_format_string)
+            total_space, used_space, free_space = shutil.disk_usage(mount_dir)
+            percentage_used = used_space / total_space
+            if (
+                percentage_used > FULL_DISK_PERCENTAGE_THRESHOLD
+                and free_space < MINIMUM_BYTES_LEFT_ON_DISK_THRESHOLD
+            ):
+                msg = (
+                    f"Low disk space: {byte_with_unit(free_space)} free on {mount_dir !s}."
+                    " Consider freeing up some space to ensure successful simulation runs."
+                )
+                ConfigWarning.warn(msg)
         return result
 
     @field_validator("jobname_format_string", mode="before")
@@ -143,3 +166,12 @@ def _replace_runpath_format(format_string: str) -> str:
     format_string = format_string.replace("%d", "<IENS>", 1)
     format_string = format_string.replace("%d", "<ITER>", 1)
     return format_string
+
+
+def _get_mount_directory(runpath: str) -> Path:
+    path = Path(runpath).absolute()
+
+    while not path.is_mount():
+        path = path.parent
+
+    return path

tests/ert/unit_tests/config/test_model_config.py

@@ -1,7 +1,10 @@
+from pathlib import Path
+from unittest.mock import patch
+
 import pytest
 
 from ert.config import ModelConfig
-from ert.config.parsing import ConfigKeys, ConfigValidationError
+from ert.config.parsing import ConfigKeys, ConfigValidationError, ConfigWarning
 
 
 def test_default_model_config_run_path(tmpdir):
@@ -61,3 +64,54 @@ def test_that_invalid_time_map_file_raises_config_validation_error(tmpdir):
 
         with pytest.raises(ConfigValidationError, match="Could not read timemap file"):
             _ = ModelConfig.from_dict({ConfigKeys.TIME_MAP: "time_map.txt"})
+
+
+@pytest.mark.parametrize(
+    "total_space, used_space, to_warn, expected_warning",
+    [
+        pytest.param(
+            10 * 1000**4,  # 10 TB
+            9.75 * 1000**4,  # 9.75 TB
+            False,
+            None,
+            id="Low disk space percentage on large disk",
+        ),
+        pytest.param(
+            100 * 1000**3,  # 100 GB
+            99 * 1000**3,  # 99 GB
+            True,
+            "Low disk space: 1.00 GB free on",
+            id="Low disk space small disk",
+        ),
+        pytest.param(
+            10 * 1000**5,  # 10 PB
+            9.99994 * 1000**5,  # 9.99994 PB
+            True,
+            "Low disk space: 60.00 GB free on",
+            id="Low disk space small disk",
+        ),
+        pytest.param(
+            100 * 1000**3,  # 100 GB
+            75 * 1000**3,  # 75 GB
+            False,
+            None,
+            id="Sufficient disk space",
+        ),
+    ],
+)
+def test_warning_when_full_disk(
+    tmp_path, recwarn, total_space, used_space, to_warn, expected_warning
+):
+    Path(tmp_path / "simulations").mkdir()
+    runpath = f"{tmp_path !s}/simulations/realization-%d/iter-%d"
+    with patch(
+        "ert.config.model_config.shutil.disk_usage",
+        return_value=(total_space, used_space, total_space - used_space),
+    ):
+        if to_warn:
+            with pytest.warns(ConfigWarning, match=expected_warning):
+                _ = ModelConfig(num_realizations=1, runpath_format_string=runpath)
+        else:
+            _ = ModelConfig(num_realizations=1, runpath_format_string=runpath)
+            for w in recwarn:
+                assert not issubclass(w.category, ConfigWarning)