Windows Server 2012 SMB 3.0 feature support

With the new release of Windows Server 2012 Microsoft has released a new full version of it’s SMB protocol.

Down below is listed what new features are introduced in this new version. As always the new version is backwards compatible but older operating systems will not support the newer features introduced in version 3.

The SMB 2.x protocol was introduced in Windows Server 2008 and in Windows Vista.
The SMB 3.0 protocol was introduced in Windows Server 2012 and in Windows 8.

New SMB features that are introduced in the Windows Server 2012 file server

  • SMB Transparent Failover
  • SMB Scale Out
  • SMB Multichannel
  • SMB Direct
  • SMB Encryption
  • VSS for SMB file shares
  • SMB Directory Leasing
  • SMB PowerShell

SMB Transparent Failover

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the SMB Transparent Failover functionality.
SMB 1.0- and SMB 2.x-capable clients will be able to connect to, and access, shares that are configured to use the Continuously Available property. However, SMB 1.0 and SMB 2.x clients will not benefit from the SMB Transparent Failover feature. If the currently accessed cluster node becomes unavailable, or if the administrator makes administrative changes to the clustered file server, the SMB 1.0 or SMB 2.x client will lose the active SMB session and any open handles to the clustered file server. The user or application on the SMB client computer must take corrective action to reestablish connectivity to the clustered file share.
NoteSMB Transparent Failover is incompatible with volumes enabled for short file name (8.3 file name) support or with compressed files (such as NTFS-compressed files).

SMB Scale Out

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the SMB Scale Out feature.
SMB 1.0 clients do not contain the required client functionality to access SMB scale-out file shares and will receive an “Access Denied” error message when they try to connect to a scale-out file share.
SMB scale-out file shares are always configured so that the Continuously Available property is set. SMB 2.x clients will be able to connect to SMB scale-out file shares but will not benefit from the SMB Transparent Failover functionality.

SMB Multichannel

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the SMB Multichannel functionality. SMB 1.0 and SMB 2.x clients will use a single SMB connection.

SMB Direct (SMB over Remote Direct Memory Access [RDMA])

SMB Direct is available only on the Windows Server platform and was introduced in Windows Server 2012. SMB Direct Functionality requires that the SMB client and SMB server support SMB 3.0.

SMB Encryption

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the SMB Encryption functionality.

VSS for SMB file shares

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the Volume Shadow Copy Service (VSS) for SMB file shares functionality.

SMB Directory Leasing

Both the SMB client and SMB server must support SMB 3.0 to take advantage of the SMB Directory Leasing functionality.

SMB PowerShell

SMB PowerShell management cmdlets were introduced in Windows Server 2012 and in Windows 8. Older SMB clients and SMB servers will have to continue using down-level tools for management (for example, Net.exe) and APIs (for example, Win32 APIs).

You can read more about SMB v3 here.

Windows 8 SMB 2.2 File Sharing Performance

Hi guys,

I found this white paper about the new SMB 2.2 protocol which Microsoft uses in the new Windows 8 OS.

This paper provides a preliminary analysis of the performance capabilities of the Server Message Block (SMB) 2.2 file sharing protocol with 10 gigabit Ethernet interfaces. The Multi-Channel feature, introduced with SMB 2.2 in Windows Developer Preview, enables the use of multiple physical network interfaces in an SMB 2.2 client and server. This paper assumes the reader is familiar with the basics of SMB file sharing, networking technologies, and file system performance measurement with the Iometer tool.

This information applies for the following operating systems:
Windows Developer Preview
Windows Server Developer Preview

Included in this white paper:

Hardware Shifts and Trends
Targeted Workloads
SMB Connection Scaling
Multi-Channel Performance (Preliminary)

Enjoy reading.