The consistency guarantees are what makes this interesting in my opinion.
> *
Close-to-open consistency. Once a file is written and closed, it is guaranteed to view the written data in the following opens and reads from any client. Within the same mount point, all the written data can be read immediately.*
> Rename and all other metadata operations are atomic, which are guaranteed by supported metadata engine transaction.
This is a lot more than other "POSIX compatible" overlays claim, and I think similar to what NFSv4 promises. There are lots of subtitles there, though, and I doubt you could safely run a database on it.
> * Close-to-open consistency. Once a file is written and closed, it is guaranteed to view the written data in the following opens and reads from any client. Within the same mount point, all the written data can be read immediately.*
> Rename and all other metadata operations are atomic, which are guaranteed by supported metadata engine transaction.
This is a lot more than other "POSIX compatible" overlays claim, and I think similar to what NFSv4 promises. There are lots of subtitles there, though, and I doubt you could safely run a database on it.