mount 2nd HD containing running Freebsd system

[Fbsd1]

Ricardo Jesus wrote:
> Fbsd1 wrote:
>> I have run out of space on my running 7.1 system. I have a 2nd HD 
>> containing 6.1 that I want to mount and use the 80gb /usr slice.
>>
>> What is the mount command to use?
>>
>> Thinking   mount /dev/ad1 /mnt  but un-sure how this handles the 6.1 
>> slices on that HD.
>>
> Read up http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html, 
> namely entries 9.1 and 9.2. Very detailed and helpful stuff.
> 

None of that was helpfull. Found post in questions archives from 1992 
that gave me pointer to correct direction.

Here is the solution I used.

  ls /dev/ad*   listed all the slices on both HDs.
  mount /dev/ad1s1f /mnt    mounted the /usr dir from the second HD just 
like i wanted.