Backblaze and moving large databases

Hoping a Backblaze user can help out with my query?!

I recently switched Backblaze on - still in the trial period, but pretty certain I will take the plunge for peace of mind.

Since I still have upload speeds from the days of ADSL, it’s taking its time to make the first complete backup… And I am trying to throw 1.5TB up onto their servers, which is not that much, but is enough to be adding to the time required to complete…


While this is going on - what will happen if I move large chunks of data around?
Will BB somehow know that data X that was here, is now there - and not try and back it up again? Our will I be adding to the files it is queuing, and see it try to upload the same data again?
Anyone have some idea?

Backblaze seems to do a good job handling moves and deduplication. You should be able to go ahead and move stuff around on your machine without worrying about lengthening your upload too much.


Expanding on @ChrisUpchurch’s explanation, here is what Backblaze support says about What happens if I move or rename a file

Our software contains a process called “deduplication” where files are digitally fingerprinted (checksummed) before they are sent to the server. When a file’s fingerprint (SHA-1 checksum) matches an already backed up file, but it’s renamed or moved (including drive to drive), it’s simply updated at the servers, rather than re-transmitted.

You may see these files queued for back up, but once any given file is at the front of the queue, it will be checksummed, compared against the existing backup, and “deduplicate” resulting in it being updated on the server rather than re-uploading

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Very appreciative of the replies! Many thanks, good to know!

Also if you don’t wanna hog bandwidth you could always schedule it to run overnight and pause during the day. Up to you though.