Michael Adam

Containers are designed to be ephemeral, stateless entities, but distributed applications running inside container clusters need a place to persistently store their data. Container orchestration systems like Kubernetes / OpenShift do meanwhile offer APIs for provisioning and providing persistent storage, but it is quite cumbersome to use them manually.

The implementation of SMB3 is a broad and important set of topics on the Samba roadmap. After a longer period of preparations, the first and the most generally useful of the advanced SMB3 features has recently arrived in Samba: Multi-Channel. This presentation will explain Samba's implementation of Multi-Channel, especially covering the challenges that had to be solved for integration with Samba's traditional clustering with CTDB, which is invisible to the SMB clients and hence quite different from the clustering built into SMB3.

Samba 4.0 has been released in December 2012. It is is the first release of Samba that features the Active Directory Compatible Domain Controller. But it is also a very important file server release: Samba 4.0 ships with SMB 3 enabled by default. In my SDC 2012 talk, I described the tasks for Samba to implement many of the features of SMB. In this talk, I will describe the subset of SMB3 that Samba 4.0 already offers, and report about the work in progress in the implementation of more SMB 3 features, giving an outlook of what to expect in upcoming Samba 4.1.

Learning Objectives

The implementation of advanced SMB3 features is a broad and important set of topics on the Samba roadmap. One of these SMB3 features that is currently being actively worked on is Multi-Channel, a kind of channel bonding at the SMB level intended to increase both performance and fault-tolerance of SMB sessions. It is not only one of the most generally useful features of SMB3 but also a prerequisite for enabling RDMA as a transport for SMB with SMB Direct.

Version 3 added a whole set of new features to the SMB protocol, notably all-active clustering capabilities. The two most prominent consequences are that it is now possible to run Hyper-V instances off an SMB share and that SMB supports RDMA as a transport in the guise of the so called SMB Direct.

Samba supports basic SMB3 since version 4.0, but without these more advanced features. Designs and plans have been developed for implementing SMB Direct and all that is needed for Hyper-V-support, and meanwhile, development has really begun.

Samba, the well known open source SMB server software features support for version 2.0 of the SMB protocol since version 3.6. The one omission from SMB 2.0 in Samba 3.6 is support for durable file handles. Meanwhile, Versions 2.1 and (in preview) 3.0 of the SMB protocol are available. Over the last months, the developers have worked hard on implementing "durable handles", SMB 2.1 and a basic support for SMB 3.0. This talk is a report about the development progress of these features that will be available in the next version 4.0 of Samba.