The mount_reiserfs utility attaches the ReiserFS file system residing on the device special to the global file system namespace at the location indicated by node.
This command is normally executed by mount(8) at boot time, but can be used by any user to mount a ReiserFS file system on any directory that they own (provided, of course, that they have appropriate access to the device that contains the file system).
To mount a ReiserFS volume located in /dev/ad1s1:
"mount_reiserfs /dev/ad1s1 /mnt"
mount(2), unmount(2), fstab(5), mount(8)