Incremental / Differential backup to Azure blob

Question

Is it possible to achieve incremental / differential backups using Azure Blobs? I would like to send only the pieces of data that changed. Maybe something with block blobs?

Thank you!

Answer 1

I would suggest starting to look at Page Blobs and Block Blobs architectures and how they can help you to achieve your objective. There are some limitation with each, however if you could understand how they work you can come up with a solution.

Block Blobs are targeted for streaming workload. Modification and updating block blob is a two-phase update process where you add/modify/upload all the new changes, and then in case of add modify uncommit + add and in case of new after upload, commit changes.

Page Blobs are targeted for random write workload. Page blob use immediate (one step process) update, as soon as a write request for a sequential set of pages succeeds, the write has committed.

So you can decided what kind of workload you have and then choose page or block blob. Windows Azure Storage team provided detailed info on how you can use Page Blobs to exactly the same you are looking for here:

Using Windows Azure Page Blobs and How to Efficiently Upload and Download Page Blobs