Biblio

The Cloud Native paradigm has quickly emerged as a new trend in Web Services architectures. Applications are now developed as a network of microservices and functions that can be quickly re-deployed anywhere, decoupled from their state. In this scenario, workloads are usually packaged as container images that can be quickly provisioned anywhere in a provider web service. To enforce security, traditional Docker container runtime mechanisms are now being enhanced by stronger isolation techniques such as lightweight hardware level virtualization. Such sandboxing inserts a strong boundary - the guest space - and therefore security containers do not share filesystem semantics with the host Operating System. However, the existing container storage drivers are designed and optimized to run directly on the host. In this paper we bridge the gap between traditional containers and virtualized containers. We present Deverlay, a container storage driver that prepares a block-based container root filesystem view, targeting lightweight Virtual Machines and keeping host native execution compatibility. We show that, in contrast to other block-based drivers, Deverlay can boot 80 micro VM containers in less than 4s by efficiently sharing host cache buffers among containers and reducing I/O disk access by 97.51 %.