Any Open Source Linux Distributed Storage Options Which be Deployed inside Rented KVM VPSes Without Additional Virtual Disks?

I am trying to figure out a scalable and HA solution for storing live data under production workloads like DBs, web contents, etc.. Which can be installed and setup on standard rented Linux KVM VPSes. Which only have the virtual disk which it's boots off of.

Tried looking at CephFS, requires block level storage cause it's "sits on top of the OBJ Ceph clustering".

As well as GlusterFS but it doesn't support live structured data like databases and I don't feels comfortable to make the setup harder and more complicated. By having to HA and clustering DBs separately (not to mention increasing costs further).

XteremeFS was sorta on the right set of tracks when I checked it out for decent bit. Except it's only does RAID0 at the moment. So forget about scaling and never mind HAing that...

In short are there real options that doesn't requires physical or block level storage devices nor is complicated to install and set up? Or otherwise "to make it all work together?".

Thanks very much in advance!