SMB3 Multichannel allows storage devices to use multiple network connections simultaneously and dramatically increase throughput to clients and is enabled by default on OneFS. The SMB client will automatically detect, negotiate, and use multiple network connections if a proper configuration is identified.
On the client side, use Windows 2012 or Windows 8 or later, with at least one of the following 10, 25, 40, or 100 Gb Ethernet network configurations:
- Multiple network adapters
- One or more network adapters that support RSS (Receive Side Scaling)
- One of more network adapters configured with NIC Teaming
Additionally:
- Use a high-performance nonblocking Ethernet switch.
- Avoid configuring LACP.
- If using SMB multichannel, it will automatically detect the IP addresses of both 10GbE/40GbE interfaces on the client and load balance across each of the two interfaces on the dual-ported NIC.
- SMB multichannel only works between a client and a single PowerScale node. It cannot share the load between PowerScale nodes. With SMB multichannel, Windows client connections to PowerScale node have integrated failover, and all throughput is load-balanced between NICs.
- No manual configuration is required on either the Windows client or PowerScale cluster to enable SMB multichannel.
- Each cluster interface is given its own static IP address in the same subnet – do not bond the Ethernet connections using LACP.
- Configure the client’s NIC driver as follows:
- “Max Number of RSS Queues” set to the physical core count for client’s CPU
- “Receive Side Scaling” set to “Enabled”
- “Receive Buffers” set to 4096
- “Transmit Buffers” set to 16384
- If using Windows Server 2012, make sure the “Enable Virtual Machine Queues” setting under “Virtualization” is set to disabled.
- Windows 8 clients may need the “interrupt moderation rate” in the NIC driver set to “disabled” in order to achieve optimal performance.
- SMB continuous availability can only be enabled during share creation. However, users can still update timeout, lockout, and write integrity settings when creating or modifying a share.
- SMB continuous availability is not enabled by default. An existing share needs to be re-created in order to enable CA.
For more information, see the Dell PowerScale: Solution Design and Considerations for SMB Environments white paper.