Sorry it was not so clear. Previously fallocate just allocate disk space for a local server. Now SeaweeedFS can allocate a blob on a remote storage.
I really don't understand why you aren't eager to explain the differences and what problems are being solved.
A blob has its own storage, which can be replicated to other hosts in case current host is not available. It can scale up independently of the file metadata.
Sorry, everybody has different background of knowledge. Hard to understand where the question comes from. I think https://www.usenix.org/system/files/fast21-pan.pdf may be helpful here.
They were straightforward questions. The paper you linked talks about blobs as a term for appending to files. Mostly it seems to be about wrapping and replicating XFS.
Is that why you are avoiding talking about specifics? Are you wrapping XFS?
Blobs are what lie under files, you can have a file split into multiple blobs spread across different drives, or different servers etc, and then can put it back together into a file when requested, thats how i understand it at a basic level
They also seem like they are being vague and patronizing to avoid admitting that their product is not a unique filesystem, but just something to distribute XFS.