What's the best way to back up the Dropbox folder if I don't have enough space to sync all files?

I have a similar situation.

I have a Dropbox account with more space (2TB) than the local drive my dropbox folder resides in.

I NEED to have multiple backups as my data is important. Who's isn't?  So one has to be on an external hard drive.

My Dropbox account now has "smart sync" which is marketed as allowing users to access more space than is available on there local drive.  Sounds great. But...

The first problem is backing up the local Dropbox folder. Now when I run a backup on my local Dropbox folder it tries to download the smart synced on line folders, which defeats the purpose of smart sync.  I understand from this thread that I can "unlink" the local dropbox to achieve the local backup. But that rules out automated backups. I can maybe live with that.

The next problem is backing up the online-only folders. I can't see any practical way to do this.  Say I put up 1.2 TB of data as online only.  I know I can download the folders to an external harddrive (my local PC hard drive isn't big enough) by changing my download folder location. But that is impractical to do every time with so much data.  What I need is an incremental backup. ie only those files that have changed. 

Is there any dropbox solution or third party software that anybody has used to do this?

I use Syncback for my regular backups.

It seems to me that without this functionality smart sync is worse than useless. I think I must be missing something. Hoping someone has a solution.

If not can I go back to selective sync?  and just use the online folders for off-site backup.

But this solution appears to only to cloud to cloud for Dropbox not Dropbox to external. I know that is what I'm looking to do and I believe the previous poster is too?

Can I make a suggestion? I have my DropBox account linked to a Synology NAS. That NAS has a package called CloudSync and it syncs the contents of my DropBox folder to a shared folder on that NAS. I have it set one-way, so all changes to the Dropbox folder are synced to the shared folder on the NAS. It runs every night by schedule (it can run continuously too).

So during the night all changes I made to the Dropbox folder during the day are written to the NAS.

It looks like the CloudSync would work.

But I have found a solution that works well for me.

"SyncBackPro"  can connect to Dropbox (and google drive etc) and backup or sync to anywhere. I have used SyncBack products for years and love them all I needed to do was upgrade to pro.

Thanks for your help.

Great suggestions!  I have a basic understanding of NAS.  Have just started to look into it.  It might be a tad above my "pay grade" but we need it for a lot of reasons (business and personal storage).  I got lost in the sea of RAID and DROBO and somehow find myself looking at NAS wondering if it was something we could use.

That said, I recently purchased FileZilla Pro.  It works for GDrive but not for Dropbox. Checked out SyncBackPro but looks like it's only for Windows (arrrrggghhh) I'm on a Mac and would probably need something multi-platform if possible as I have different machines set up in my house.  I feel like I might need some local geek setup for helping me figure this out.  But it feels like the right direction.  Thanks for your help!

Let me know if you know of another program that will sync Dropbox but that will work on a mac.

Hi Jane,

Yes, I understand about the place holder being local and the real file on the dropbox cloud.

SyncBackPro logs on to dropbox cloud ( once it has permission) and can perform its backup function between dropbox cloud and an external hard drive. 

I assume that many dropbox smart sync uses rely completely on dropbox for their smartsynced file security. I am sure dropbox does a great job of backing up the system, but **bleep** happens. I have recently had to retrieve files from 14 years ago that relates to a problem worth $1.4 M. I could do that because I have good backups. It would be great if dropbox provided this functionally to its customers.

I love Dropbox though and am pleased to have found a way to continue using it.

Do you happen to know if there is an option like SyncBackPro for mac? FileZilla Pro does for Google Drive what SBP does for Dropbox with Windows.  Would love to solve this problem!

While I work on a Mac, we do have a PC in our home. I'm actually contemplating getting a 4TB HDD added to our main PC strictly to have the full contents of Dropbox downloaded and kept locally there as a backup.  Wish Dropbox made it easier but I love it and want to use it.  Just have to figure out to have local backups copies of my data too.