backup software to backup across wan

The two sites would just be the office and the home office.  Both have a 2mbit upload speed.  I was thinking of transferring the data over a secure sftp connection.

And how many servers/computers are invloved in this?
If I'm doing my calculations right (and please someone correct me if i am wrong!) it would take roughly 42 hours for 300GB of data to be transferred over a 2mb line, assuming full capacity is utilized, nothing else taxing the resource. How often are you planning to do a full backup? Is there an entire weekend that no one is working at that off site?

3 servers.  I think you're wrong on the time calculation.  A 300gig upload would take 15 day(s), 13 hr(s), 47 min(s),  over a 2mbit connection.  It seems I could only do that once per year at the most.  I would probably need to throttle the connection at 1mbit so it would take twice as long.  This doesn't even seem feasible.  Yet there are companies out there offer paid online backup solutions like Barracuda backup service.  they charge $150 per month if I backup 300gigs.  

It seems like if their appliance\software can do it then I should be able to set up a NAS at my second location and use my own backup software which is why I started this question.  I want to know which software works best for this type of backup.

It's possible to do something like this on a continuous backup scheme, if you can sync the two storage devices once over a fast link.  See, for example, HP's Storage Mirroring product, that will replicate systems by sending only differences once the data is completely backed up.  There are also D2D backup devices that can do similarly; they mimic one or more tape libraries, and then through deduplication (block-level single-instance storage) can replicate by sending only changes and some metadata over the WAN.  Search for "d2d backup system".

My concern, though, is as much for the mechanics of the backup, as well as the concept of archival storage.   Is it possible that you would ever -- for either legal or business rules -- need to retrieve data from a year ago?   Or five years ago?  (Some of those reasons could include a lawsuit or internally to gather evidence of employee fraud/embezzlement)  Disk is a bad way to try to store archival data.  Tape's still the best for that, and a 'green' technology, since tape drives use way less electricity than disks, and a tape on a shelf uses almost no electricity (aside from environmental temperature/humidity control).

I agree with Self Govern that you should still be backing up to tape whether you do it at your Production site or your Secondary site;

otherwise all you have is duplication, not backup.

Doubletake sounds interesting.  I've heard I could do the same thing with Acronis.  Do you normally do a full backup each night to your tape drive?

Nice solution.  I think for now we are holding off on the off site replication.  

Right now my plan is to upgrade the LTO2 drive to removable disks.  The disk would be large enough to hold images and data of all the servers.  We would do a full backup each night.  

Should I create an image each night or maybe a weekly image and just data every night?  I also have an onsite NAS device.  Right now I'm just doing a full data backup every night.  It only holds 5 days worth.  

You could do a full image every Friday and an incremental backup every other night.

Do you not have a requirement to be able to retrieve data from weeks/months/years earlier?

Right now we do not have that requirement.  We do keep some tapes for up to 6 months though.  I don't think I'm going to buy that many removable drives.  I was thinking I could modify the NAS to hold backups for a longer period of time if needed.

Just bear in mind that when the boss comes looking for that critical email/document/database record he last saw 12 months ago you won't be in a position to retrieve it.

Happens to me all the time which is why I keep 4 weeks of weekly  and  7 years of monthly backup tapes offsite.

I would suggest you make sure the business is aware of that before you commit yourself to a particular position.

If they sign off on it (make sure you keep a copy) then no problems your ass is covered.

Thanks for your quick reply.  We will be discussing our options soon and I will be sure to mention that.  At one point we only had backups going back 7 weeks.  I've only had 1 request for an older file which is why I added 6 monthly tapes.

I'm hoping I can modify my NAS device to hold at least a years worth of incremental backups.  If they want longer than a year then tapes may be the way to go instead of the removable disk option.