1 file system, 2 drives?

[John Almberg]

One of my clients has a server that hosts big public-access type videos. 
He started off with a separate 200G drive just for video storage 
(FreeBSD is on another drive). This video storage drive is mounted as 
/videos.

He's just bought another drive, but now I'm thinking of what to do with 
it...

I know this is probably impossible, but FreeBSD can do so many 
miraculous things, that I can't help asking...

Is it possible to use the second drive to 'expand' the /videos file 
system? So it would miraculously look like a single 400G drive?

I ask this, because logically, I"m going to use the second drive the 
same way as the first: to store videos. It will be really awkward to 
have two mount points, and try to decide which video should get stored 
on which drive. And no doubt it will get more complex as we go along. It 
would be much simpler if this logical drive could just expand as needed.

Any ideas much appreciated.

-- John