the -L in dump

[srenna at vdbmusic.com]

Was working my way through dump and was going over what the
-L switch is used for.  I guess one would use this when you
are dumping a mounted file system correct?

Here's what I've been trying to do, dump all of / without
dumping /tmp, /proc, /mnt, and /entropy.  I've already
learned to use the nodump flag with some help from a list
member and now I want my dump to run correctly.

My commandline is as follows:

dump -0 -a -f /mnt/backup_drive/ad0backup/main_backup11_03
-h 0 -L -u /

Will a command like this dump the entire file system  for
me for later restore should a complete meltdown happen?