Fixing Windows 11 Remote File Sharing and SMB Connectivity Optimization

Unlocking Blazing-Fast SMB Performance on Windows 11

As an experienced IT professional, I’ve encountered countless challenges when it comes to remote file sharing and optimizing SMB (Server Message Block) connectivity. In this comprehensive guide, I’ll share practical tips and in-depth insights to help you fix common issues and unleash the full potential of your Windows 11 network.

Understanding the Challenges of SMB Connectivity

SMB is the default network file-sharing protocol used in Windows, but its performance can be influenced by various system and network factors. One common complaint is slow file transfer speeds, especially when dealing with multiple small files or large image backups over a 1GbE network.

The culprits behind these performance issues can range from SMB signing and encryption, storage constraints, network latency, and even antivirus interference. Additionally, the way Windows 11 handles file creation and small file transfers can contribute to sluggish performance.

Samba Configuration: The Game-Changing Breakthrough

During my research, I came across an insightful Reddit post that revealed a remarkable Samba configuration optimization that can dramatically improve SMB performance on Windows 11. The author of the post had set up an OpenMediaVault (OMV) NAS system and conducted thorough testing to address their own file-sharing challenges.

Before the Samba configuration changes, the user experienced highly inconsistent and slow performance, with file transfer speeds ranging from 30-60MBps (bytes, not bits) and image backup speeds fluctuating wildly between 350-600Mbps (bits, not bytes). However, after implementing the following Samba settings, the results were astounding:

• Copying 13 video files (360MB total): 86-95MBps
• Image backup writing: 850-940Mbps

The improvement in both throughput and consistency was remarkable. The author noted that the performance became “dramatically more consistent and for most of the image backup was near line speed. No more sudden peak/valley fluctuations in the network graph.”

Samba Configuration Settings for Optimal SMB Performance

To achieve these impressive results, the following Samba configuration settings were applied:

1. getwd cache = true
2. write cache size = 1024000
3. min receivefile size = 16384

These settings can be added to the Advanced Settings section of the SMB/CIFS service in the OMV GUI. The author mentioned that the specific values used were from a reference article, but they can be further adjusted based on your needs and the official Samba documentation.

It’s worth noting that the write cache size setting may not be necessary in newer Samba versions (4.12 and beyond), as the caching functionality has been improved.

Addressing Additional SMB Performance Factors

While the Samba configuration changes were the primary game-changer, there are other factors to consider when optimizing SMB performance on Windows 11:

1. SMB Signing and Encryption: These security features can introduce a performance penalty, so it’s essential to strike a balance between security and speed. Microsoft recommends leaving SMB signing and encryption enabled, as they provide critical protection against attacks.

2. Storage Performance: Ensure that the backing storage (e.g., SSD, HDD) has the required performance characteristics to meet your desired network throughput. Use tools like robocopy with the /J parameter to perform unbuffered I/O for files larger than 1GB.

3. SMB Direct (SMB over RDMA): This feature can help reach high network transfer speeds without causing excessive CPU utilization. Verify that SMB Multichannel is enabled and functioning correctly.

4. Network Offloading Technologies: Ensure that network offloading features, such as large maximum transmission unit (MTU) and bandwidth throttling settings, are properly configured.

5. Antivirus and Endpoint Protection: Temporarily disable file scanning and network filter drivers to determine if they are contributing to the performance degradation.

6. Small File Transfers: Understand that small file transfers (hundreds, thousands, or millions of files less than 1MB) can be inherently slower due to the overhead associated with file creation and SMB protocol operations. Use tools like robocopy with the /MT parameter or third-party multi-threaded file copy utilities to improve small file transfer performance.

7. Office Document Slow Openings: If you’re experiencing slow Office document openings, particularly over WAN connections, try disabling leasing on the SMB server. This can help resolve the issue, though it may impact other features that rely on leasing.

Troubleshooting Slow Remote File Sharing and Connectivity

If you’re still experiencing issues with remote file sharing and SMB connectivity on your Windows 11 systems, here are some additional troubleshooting steps to consider:

1. Check Network Errors: Look for signs of network-level issues, such as packet loss, which can cause TCP congestion and throttle the overall throughput.

2. Analyze TCP/IP Settings: Investigate the TCP/IP settings on both the client and server, including TCP window scaling, TCP receive window auto-tuning, and the use of TCP templates.

3. Disable Receive Segment Coalescing (RSC): As mentioned earlier, disabling RSC on the Windows 10 client can sometimes resolve performance problems.

4. Verify NIC Configuration: Ensure that the network interface cards (NICs) on both the client and server are properly configured, with the correct port settings and potentially try a different switch if necessary.

5. Test with Alternative File Transfer Tools: Utilize robust file transfer utilities like AzCopy or third-party tools that support multi-threaded file copying to see if the performance improves.

6. Consider Replicating to a Local File Server: If Office document openings are consistently slow, you can try replicating the files to a local file server to see if that resolves the issue.

Remember, troubleshooting network and file-sharing performance can be a complex endeavor, but the tips and insights provided in this article should give you a strong foundation to tackle the most common challenges you may encounter on your Windows 11 systems.

For more IT-related advice and solutions, be sure to visit https://itfix.org.uk/, where our seasoned IT professionals are dedicated to providing practical, in-depth guidance to help you optimize your technology infrastructure.