USB and fast booting

I have had to work around this issue a few times. In the case of a root filesystem it's not difficult as the kernel can be made to wait until the device is available before continuing. For other filesystems it's more difficult. I generally mount them by label or by UUID in /etc/fstab. What I would really like is to be able to specify, e.g. in fstab, what the system should do if the device is not (yet) available i.e. wait, skip the mount, or background it. In comparison, NFS mounts can be backgrounded if the server is not immediately available. An alternative is to automount the device when it's first used, and wait at that point if it's not available. See my bug report at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=482273