Backing up files to another location

I'll tell you what I am trying to do then maybe someone can advise. I apolgise I know very little about Unix but I'm a quick learner (actually I need to be in this instance)

I have directory I want to backup, now df shows me this and it is /usr I need to back up, as you can see not a whole load of room to do this. Now if this was a windows box I'd just map a drive (I've got stacks of space elsewhere I can FT to a lan or FTP outside) and bobs your uncle. However as I'm finding out this is more complicated.

Filesystem    1K-blocks     Used    Avail Capacity  Mounted on
/dev/idad0s1a    253678    84224   149160    36%    /
devfs                 1        1        0   100%    /dev
/dev/idad0s1e    253678    12066   221318     5%    /tmp
/dev/idad0s1f  29976132 15299206 12278836    55%    /usr
/dev/idad0s1d    253678   130396   102988    56%    /var

If I want to take all of /var I don't have enough room on the local machine as I said I have two FTP sits I can go to both have in excess of 50gb.

Now before anyone says put in another drive I'll explain, this is a mail server and it takes me about 3 hours to get there and I need to run a FSCK job in single user mode, now it takes about 3 hours to get to this server so I'd like to start the job before I leave instead of siiting by the machine waiting for the backup. I'm sure you get my drift.

Now in windows it is possible to zip and FTP at the same time or as I said before I could map a drive and just copy the files over. But as far as I understand it put or mput won't do everything in /var it will just do all files in that directory.
There are to many folders in /var for me to individually go through them all, I want this to be automatic.

Now for arguments sake lets say this machine is 192.168.1.1 and the internal ftp is 192.168.1.2 and allows anonm access whilst the external ftp ftp.madeupname.com only allows authenticated.

What are my choices now and maybe in the future.
 
If you need more info this is a G1 DL 360 and the drives are Mirrored in hardware so no room for an extra drive USB is V1 I think or could be V1.1 so would be a slow transfer unless I stuff a USB 2 controller in and that would still mean I'd have to go there and watch this, however as a future deal maybe I should do this. To make thing worse though I'm still a learner and adding a USB drive would mean someone telling me how configure it.

Breaking the mirror and putting in a larger drive and using the space on that could be an option. though.

Oh yes FreeBSD 5.5 I think

Anyway all help gratefully accepted.