Failing NFS mounts with the -b option take a lot of time, because they fork AFTER an attempt has failed. And that normally takes a lot of time. So I have written that patch, which fixes the behaviour by forking even before the first attempt is made. http://www.freebsd.org/cgi/query-pr.cgi?pr=103089 But now I wonder weather it wouldn't be better to introduce an option like nocrit for non critical mounts in sbin/mount that generally forks mounts with that option into the background. It would be useful for all kinds of replaceable drives and network shares. Especially in an ever changing environment such as a Laptop. Now why not amd you say, the answer being that it costs significant CPU time when using such a mount. That does not matter on an optical drive, but when you want to build the world on an external HD, it makes a difference.