Measuring SMB throughput by using Robocopy

Learn to measure SMB throughput between the SMB share and the Windows client by using the in-built robocopy utility in Windows.

About this task

To assess the data transfer performance between the SMB share and the Windows client, use the built-in robocopy utility. This helps identify potential performance bottlenecks or latency issues in the SMB communication.

Procedure

  1. On the Windows client, open a command prompt with administrative privileges.
  2. Run the following command to copy a large test file or directory from the local system to the mounted SMB share (or vice versa).
    robocopy C:\path\to\source \\SMB_SERVER\sharename /E /Z /NP /R:0 /W:0 /LOG:robocopy_log.txt
    Where,
    C:\path\to\source
    Is the path of the test data.
    \\SMB_SERVER\sharename
    Is the SMB share path.
    /Z switch
    The /Z switch enables restartable mode, /NP disables progress display for better performance, and /LOG logs the output.
    The robocopy_log.txt is emitted to the path specified.
  3. Check the log metrics.
    After the robocopy log is emitted, check the file for the following metrics:
    • Bytes transferred
    • Transfer time
    • Throughput (in MB/min)
    These metrics can help determine whether throughput is within expected limits based on your network and storage setup. If performance is lesser than expected, investigate factors such as network latency, SMB version, or server-side resource constraints.