Three links for you: https://jira.mongodb.org/browse/SERVER-6178 https://jira.mongodb.org/browse/SERVER-6178 http://www.noah.org/wiki/Kill_-9_does_not_work ht

Three links for you: https://jira.mongodb.org/browse/SERVER-6178 https://jira.mongodb.org/browse/SERVER-6178 http://www.noah.org/wiki/Kill_-9_does_not_work http://www.noah.org/wiki/Kill_-9_does_not_work http://stackoverflow.com/questions/223644/what-is-an-uninterruptable-process http://stackoverflow.com/questions/223644/what-is-an-uninter... The first is the bug I reported to 10gen about their MongoDB setup. Contained in the bug report is the set of commands I used to reproduce the issue so that you can see it yourself. The second and third links are about processes in uninterruptible sleep, which is the state my MongoDB processes were in. It should give more detail than I'm about to give. Linux processes all have a state (running, sleeping, etc). One of those states is "Uninterruptible Sleep". Only the kernel can change a process's state. Uninterruptible sleep ("D" in `top`) is a state in which the process will receive no interrupts (signals). Since the `kill` command is just a glorified signal sender, it ceases to work for those processes.