# CoronaFS

CoronaFS is PhotonCloud's mutable VM-volume layer.

Current implementation:

- custom block backend, not NFS
- control API on `coronafs-server`
- raw volume data stored under `/var/lib/coronafs/volumes`
- exported to workers as `nbd://` targets via `qemu-nbd`
- primary consumer: `plasmavmc` managed VM volumes

Intentional split:

- mutable VM volumes live on CoronaFS
- immutable VM images live in LightningStor object storage

This keeps VM root/data disks on a shared block path while leaving image distribution on the object layer.