Filesystem test suites

"Full testing of ext4 takes about 20 hours, but an intern he worked with was able to reduce that to two hours by sharding the tests in Google Compute Engine."

Without details onnumber of nodes and ballpark monetary costs developers can expect to pay for one 2-hour test run on GCE it's kind of difficult to get excited about using GCE.

That said, 10 minutes for a local smoke test is quite reasonable.