Mastering Robocopy: Reliable File Transfers Made Easy

Robocopy (Robust File Copy) is a powerful command-line directory and file replication command built into Windows. Whether you’re managing local file transfers or coordinating data movement across network servers, Robocopy offers superior reliability and features compared to standard copy commands.

Basic Syntax

The basic syntax for Robocopy is:

robocopy <Source> <Destination> [<Files>] [<Options>]

Common Scenarios and Solutions

1. Local File Copy with Full Directory Structure

To copy an entire directory structure while maintaining all attributes:

robocopy C:\SourceFolder D:\DestFolder /E /COPYALL /R:3 /W:10

Key switches used:

/E: Copies directories and subdirectories, including empty ones
/COPYALL: Copies all file information (equivalent to /COPY:DATSOU)
/R:3: Number of retries on failed copies (3 times)
/W:10: Wait time between retries (10 seconds)

2. Network Share Replication

When copying between servers:

robocopy \\Server1\Share1 \\Server2\Share2 /MIR /Z /MT:16 /R:5 /W:15 /TEE /LOG:C:\Logs\CopyLog.txt

Key switches:

/MIR: Mirrors directory tree (equivalent to /E plus /PURGE)
/Z: Copy files in restartable mode
/MT:16: Uses 16 threads for multi-threaded copies. Default is 8. Increasing the value speeds up the copy but the benefits aren’t linear
/TEE: Displays output in console and log file
/LOG: Creates detailed log file

3. Backup Solution with File Selection

To create a backup of specific file types:

robocopy C:\WorkFiles D:\Backup *.doc *.docx *.pdf /S /XO /MT:8 /NFL /NDL

Key switches:

/S: Copies subdirectories (but not empty ones)
/XO: Excludes older files (only copies newer files)
/NFL: No File List – doesn’t log file names
/NDL: No Directory List – doesn’t log directory names

Essential Switches Reference

File Selection Options

/A: Copies only files with Archive attribute
/M: Copies and resets Archive attribute
/XF [files]: Excludes specific files
/XD [dirs]: Excludes specific directories
/MAX:n: Maximum file size
/MIN:n: Minimum file size

Copy Options

/COPY:copyflags: What to copy (D=Data, A=Attributes, T=Timestamps, S=Security, O=Owner, U=aUditing)
/DCOPY:T: Copy directory timestamps
/SEC: Copy files with security
/TIMFIX: Fixes file times on all files

Retry Options

/R:n: Number of retries
/W:n: Wait time between retries
/REG: Save retry settings in registry

Logging Options

/LOG:file: Output status to LOG file
/TEE: Output to console and log file
/NP: No Progress – don’t display progress
/L: List only – don’t copy files

Advanced Use Cases

1. Large File Transfer with Progress Monitoring

For transferring large files with progress updates:

robocopy C:\LargeFiles D:\Destination /E /Z /MT:32 /COPYALL /R:5 /W:30 /TEE /LOG+:C:\Logs\Transfer.log /MON:1

/MON:1: Monitors source for changes
/LOG+: Append to existing log file

2. Incremental Backup Solution

Create an incremental backup copying only newer files:

robocopy C:\Production D:\Backup /MIR /FFT /DST /XO /W:5 /R:2 /Z /NP /LOG:C:\Logs\Backup_%date:~-4,4%%date:~-7,2%%date:~-10,2%.log

/FFT: Assumes FAT file timing
/DST: Compensates for DST changes
/XO: Excludes older files

Best Practices

Always Test First: Use /L switch to list operations without copying
Use Logging: Implement /LOG for troubleshooting and audit trails
Adjust Threads: Use /MT based on hardware capabilities
Monitor Progress: Implement /TEE for real-time monitoring
Handle Large Files: Use /Z for network resilience

Conclusion

Robocopy is an invaluable tool for system administrators and IT professionals. Its robust feature set makes it ideal for everything from simple file copies to complex backup solutions. Understanding these switches and their applications will help you build reliable file management solutions.

Remember to always test your commands in a safe environment first, especially when using switches like /MIR that can overwrite destination files. Happy copying!