MoSMB – Linux based SMB 3 server (Server Message Block 2/3 protocol)

The diagram depicts an SMB3 Use Case for NAS. It is taken from SNIA’s presentation

MoSMB is designed to be a fully compliant, light-weight, low footprint, proprietary license bearing ANSI C server component in user space which can be integrated into Network Attached Storage (NAS) storage stacks quickly and efficiently. MoSMB’s enterprise-class architecture supports high performance, high scalability and High availability (HA) to meet the present and future needs NAS manufacturers and allows them to expand their NAS offering by including SMB  protocol with a dramatically decreased time to market ! MoSMB also offers the following advanced features:

Active Directory Integration

Kerberos support

• Signing and Encryption


Persistent Handles v1 & v2

Transparent failover and continuous availability using Witness protocol

Distributed Mo-SMB file shares as Distributed File System

• Heterogenous storage support at share level

Active-Active Scale-out cluster support


Why the need to develop MoMSB – an  SMB 3.0 Protocol implementation?

There are mainly two file sharing protocols supported on any Network Attached Storage – NFS & SMB or earlier called as CIFS.

NAS has a number of advantages over SAN today since

  • NAS is easier to manage
  • NAS can get 90+ of the performance of SAN
  • Lower administrative costs
  • More Flexible
  • Granularity is file/directory/volume

In 2012, Microsoft developed SMB 3.0 protocol mainly to address the NAS storage and not DAS (Direct Attached Storage).

The SMB 3.0 features for NAS include

  • SMB 3 Multi Channel provides speed & failover
  • SMB Direct/RDMA
  • SMB 3 Persistent Handles
  • SMB 3 File/Directory leases (allows client to cache) NAS
  • SMB3 is cheaper, faster, & more reliable due to multi-pathing support using multiple NICs

Since most NAS boxes are linux-based, it is a necessity to have a good SMB 3 implementation on linux. Some of the solutions in the market today are

  • SAMBA, the SMB stack on linux for the past 30 years. Samba supports SMB version 1, 2, 2.01 and few features of SMB3. Samba has its own set of problems like performance, scalability etc. due to the baggage.
  • Some companies like EMC, Netapp have their own implementations of SMB3 stack on linux developed over years by large teams

Ryussi has seen this gap and developed a ready-to-market solution for all NAS vendors today. Ryussi has developed MoSMB – an ANSI C implementation of SMB versions 2 & 3 protocol. Apart from the advanced SMB3 features supported by MoSMB, it gives enterprise features such as high performance, high scalability, cluster friendly and a management API.

Value added by the SMB 3 features such as witness server, active-passive and active-active scale-out cluster, distributed file-system support, etc. will be discussed.

Product Features

File & Print

  • SMB3 File Server
  • SMB3 Printing
  • Named Pipes

High Performance

  • Receive Side Scaling
  • ODX Support
  • Multichannel
  • SMB Direct
  • Directory Leasing and Caching

Security & Authentication

  • Encryption Signing
  • SAD Integration (LDAP/Kerberos)


  • Cluster Support
  •  RPC
  • Witness Protocol
  •  Persistent/Durable Handles

Client Support

  • Hyper V – Live Migration
  •  SQL Server


  • SMI-S
  • Remote VSS
  •  Powershell

For more information check out the website