Mounting ISOs under FreeBSD 5.x
Under FreeBSD 4.x and prior, a utility called vnconfig was used for both creating and mounting RAMdisks and mounting ISOs as virtual drives. However, vnconfig is no longer used in FreeBSD 5.x. To mount an image under a FreeBSD 5.x system, you'll need to use mdconfig, like this:
ph34r# mdconfig -a -t vnode -f /path/to/image.iso -u 1 ph34r# mount -t cd9660 /dev/md1 /mnt/cdrom
Note that -u 1 matches up with /dev/md1. If you needed to mount more than one device this way, you would use -u x with /dev/mdx as appropriate.
To dismount the ISO and destroy the virtual device (thus allowing you to do things like write to the ISO file), you would issue the following:
ph34r# umount /dev/md1 ph34r# mdconfig -d -u 1