diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index 77f42f7f9c937b..fb1989150c15d8 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -66,8 +66,12 @@ def testNoArgFunctions(self):
         NO_ARG_FUNCTIONS = [ "ctermid", "getcwd", "getcwdb", "uname",
                              "times", "getloadavg",
                              "getegid", "geteuid", "getgid", "getgroups",
-                             "getpid", "getpgrp", "getppid", "getuid", "sync",
+                             "getpid", "getpgrp", "getppid", "getuid",
                            ]
+        # gh-102184: Don't test sync() by default since it might cause heavy
+        # I/O and block for a long time.
+        if support.is_resource_enabled('largefile'):
+            NO_ARG_FUNCTIONS.append("sync")
 
         for name in NO_ARG_FUNCTIONS:
             posix_func = getattr(posix, name, None)
diff --git a/Misc/NEWS.d/next/Tests/2023-02-23-17-38-36.gh-issue-102184.W71J5G.rst b/Misc/NEWS.d/next/Tests/2023-02-23-17-38-36.gh-issue-102184.W71J5G.rst
new file mode 100644
index 00000000000000..5bbfc5b2dd5966
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2023-02-23-17-38-36.gh-issue-102184.W71J5G.rst
@@ -0,0 +1 @@
+Test ``os.sync()`` only if "largefile" resource is enabled.