diff --git a/devenv/checks/diskfree.py b/devenv/checks/diskfree.py
new file mode 100644
index 00000000..51e2b705
--- /dev/null
+++ b/devenv/checks/diskfree.py
@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+import shutil
+
+from devenv.lib_check.types import checker
+from devenv.lib_check.types import fixer
+
+tags: set[str] = {"builtin"}
+name = "there should be sufficient host disk space"
+
+
+@checker
+def check() -> tuple[bool, str]:
+    disk_total, disk_used, disk_free = shutil.disk_usage("/")
+    disk_gib_free = disk_free / (1024**3)
+
+    if disk_gib_free < 10000:
+        return (
+            False,
+            f"You have less than 10 GiB disk free ({disk_gib_free} GiB free). "
+            "You might start to encounter various problems when using colima.",
+        )
+
+    return True, ""
+
+
+@fixer
+def fix() -> tuple[bool, str]:
+    return (
+        False,
+        """
+
+We can't autofix this, only you can clean up your own disk.
+
+You might want to try cleaning up unused Docker resources:
+   docker system prune -a
+""",
+    )
diff --git a/devenv/checks/test.py b/devenv/checks/test.py
deleted file mode 100644
index 0a7a6ba2..00000000
--- a/devenv/checks/test.py
+++ /dev/null
@@ -1,36 +0,0 @@
-from __future__ import annotations
-
-import os
-
-from devenv.lib import fs
-from devenv.lib import proc
-from devenv.lib_check.types import checker
-from devenv.lib_check.types import fixer
-
-tags: set[str] = set()
-name = "foo"
-
-
-@checker
-def check() -> tuple[bool, str]:
-    if os.path.exists(f"{fs.gitroot()}/foo"):
-        return True, ""
-    return False, f"{fs.gitroot()}/foo doesn't exist"
-
-
-@fixer
-def fix() -> tuple[bool, str]:
-    try:
-        proc.run(
-            (
-                "/bin/bash",
-                "-c",
-                """
-echo blah > foo
-""",
-            ),
-            cwd=fs.gitroot(),
-        )
-        return True, ""
-    except RuntimeError as e:
-        return False, f"{e}"
diff --git a/devenv/lib/colima.py b/devenv/lib/colima.py
index f9c9e680..2f7715da 100644
--- a/devenv/lib/colima.py
+++ b/devenv/lib/colima.py
@@ -186,6 +186,10 @@ def start(restart: bool = False) -> ColimaStatus:
             "colima",
             "start",
             "--verbose",
+            # we're overprovisioning a 512 GiB disk here which is fine because
+            # the disk doesn't reserve space and is copy-on-write
+            "--disk",
+            "512",
             # this effectively makes the vm's resolvectl status use:
             # DNS Servers: 8.8.8.8 1.1.1.1 192.168.5.2
             # https://lima-vm.io/docs/config/network/user/