The error message clearly indicates that Robocopy isn't receiving parameters as expected. The fundamental problem lies in how PowerShell passes arguments to the Robocopy executable. The current string concatenation approach causes all parameters to be treated as a single argument.

When calling external commands from PowerShell, each parameter should be passed as a separate argument. Here's the corrected version of your script:

param ($configFile)

$config = Import-Csv $configFile
$what = "/COPYALL", "/B", "/SEC", "/MIR"
$options = "/R:0", "/W:0", "/NFL", "/NDL"
$logDir = "C:\Backup\"

foreach ($line in $config)
{
    $source = $($line.SourceFolder)
    $dest = $($line.DestFolder)
    $logfile = Join-Path $logDir "$(Split-Path $dest -Leaf).log"
    
    robocopy $source $dest @what @options "/LOG:$logfile"
}

The script now properly handles parameter passing by:

• Splitting switches into separate array elements
• Using the array splatting operator (@) for cleaner parameter passing
• Using Join-Path for safer path concatenation
• Placing the log file path in quotes to handle spaces

For more complex scenarios, consider these additional improvements:

# Example of dynamic parameter building
$robocopyParams = @{
    Source = $source
    Destination = $dest
    Mirror = $true
    LogFile = $logfile
    Retry = 0
    Wait = 0
    NoFileLogging = $true
    NoDirLogging = $true
}

# Convert to robocopy arguments
$arguments = @()
$arguments += $robocopyParams.Source
$arguments += $robocopyParams.Destination

if ($robocopyParams.Mirror) { $arguments += "/MIR" }
if ($robocopyParams.LogFile) { $arguments += "/LOG:$($robocopyParams.LogFile)" }

Start-Process robocopy -ArgumentList $arguments -NoNewWindow -Wait

Add robust error handling to your script:

try {
    $process = Start-Process robocopy -ArgumentList $arguments -NoNewWindow -Wait -PassThru
    if ($process.ExitCode -ge 8) {
        Write-Warning "Robocopy completed with warnings (Exit code: $($process.ExitCode))"
    }
    elseif ($process.ExitCode -ne 0) {
        throw "Robocopy failed with exit code $($process.ExitCode)"
    }
}
catch {
    Write-Error "Robocopy execution failed: $_"
}

When trying to execute RoboCopy through PowerShell, many developers encounter the frustrating "No Destination Directory Specified" error. The issue typically stems from incorrect parameter passing in the command string construction.

In your current implementation, there are several critical issues:

# Problematic line:
robocopy \"$source $dest $what $options /LOG:MyLogfile.txt\"

The main problems are:

• All parameters are concatenated into a single string argument
• Quotes are incorrectly placed around the entire command
• The log file path isn't using your $logfile variable

Here's the fixed version of your script:

param ($configFile)

$config = Import-Csv $configFile
$what = "/COPYALL /B /SEC /MIR"
$options = "/R:0 /W:0 /NFL /NDL"
$logDir = "C:\Backup\"

foreach ($line in $config)
{
    $source = $($line.SourceFolder)
    $dest = $($line.DestFolder)
    $logfile = $logDir + (Split-Path $dest -Leaf) + ".log"
    
    robocopy $source $dest $what $options /LOG:$logfile
}

The fixed script makes these crucial changes:

• Removed the quotes around the entire command
• Properly separated each argument
• Fixed the typo in $logDir variable
• Corrected the /SEC parameter formatting
• Actually used the generated $logfile path

For more complex scenarios, consider these patterns:

# With retry and thread count
robocopy $source $dest /MIR /MT:8 /R:3 /W:5 /LOG+:$logfile

# With file size filtering
robocopy $source $dest /MIN:1048576 /MAX:104857600 /LOG:$logfile

# With progress display
robocopy $source $dest /MIR /TEE /NP /LOG:$logfile

When RoboCopy fails unexpectedly:

• Check the last exit code: $LASTEXITCODE
• Add /V for verbose logging
• Use /L for dry-run testing
• Consider /UNILOG: for Unicode log files

For large directory trees:

• Use /MT for multi-threading (default 8 threads)
• /J enables unbuffered I/O for large files
• /NP removes progress percentage calculation overhead
• Schedule during off-peak hours for network copies