---
tags:
  - DFS
  - Replication
  - PowerShell
---

## Purpose
Report the directional replication backlog between the DFS member servers in the script.  Set the member names to the intended deployment and run from a PowerShell session with access to its DFS replication configuration.

## Script
You may want to check that replication is occurring bi-directionally between every member server in your DFS deployment.  I wrote a script below that effectively shows you every replication group and each directional backlog status.

```powershell
# --- CONFIG ---
$Members = @("LAB-FPS-01","LAB-FPS-02")
$SummarizeAcrossFolders = $true  # $true = one line per direction per RG; $false = per-folder lines

function Invoke-DfsrBacklogStatus {
    param(
        [Parameter(Mandatory)] [string] $RG,
        [Parameter(Mandatory)] [string] $RF,
        [Parameter(Mandatory)] [string] $Send,
        [Parameter(Mandatory)] [string] $Recv
    )

    $out = & dfsrdiag backlog /rgname:"$RG" /rfname:"$RF" /sendingmember:"$Send" /receivingmember:"$Recv" 2>&1 | Out-String
    $outTrim = ($out -split "`r?`n" | ForEach-Object { $_.Trim() }) | Where-Object { $_ -ne "" }

    if ($out -match 'No Backlog') {
        return [pscustomobject]@{ Status="No Backlog"; Count=0; Detail=$null }
    }

    $count = $null
    $countLine = $outTrim | Where-Object { $_ -match '(?i)backlog' } | Select-Object -First 1
    if ($countLine -and ($countLine -match '(\d+)')) { $count = [int]$matches[1] }

    $detail = ($outTrim | Select-Object -First 8) -join " | "

    return [pscustomobject]@{
        Status = if ($count -ne $null) { "Backlog: $count" } else { "Backlog/Check Output" }
        Count  = $count
        Detail = $detail
    }
}

$groups = Get-DfsReplicationGroup | Sort-Object GroupName

foreach ($g in $groups) {
    $rg  = $g.GroupName
    $rfs = Get-DfsReplicatedFolder -GroupName $rg | Sort-Object FolderName

    Write-Host ""
    Write-Host ("== Replication Group: {0} ==" -f $rg)

    foreach ($send in $Members) {
        foreach ($recv in $Members) {
            if ($send -eq $recv) { continue }

            if ($SummarizeAcrossFolders) {
                $worstCount = 0
                $nonZero = @()
                $errorsOrDetails = @()

                foreach ($rfObj in $rfs) {
                    $rf  = $rfObj.FolderName
                    $res = Invoke-DfsrBacklogStatus -RG $rg -RF $rf -Send $send -Recv $recv

                    if ($res.Status -ne "No Backlog") {
                        $nonZero += [pscustomobject]@{ RF=$rf; Status=$res.Status; Count=$res.Count; Detail=$res.Detail }
                        if ($res.Count -ne $null -and $res.Count -gt $worstCount) { $worstCount = $res.Count }

                        # ✅ FIX: ${rf} avoids the ':' parsing issue
                        if ($res.Detail) { $errorsOrDetails += "RF=${rf}: $($res.Detail)" }
                    }
                }

                if ($nonZero.Count -eq 0) {
                    Write-Host ("{0} -> {1}: No Backlog" -f $send, $recv)
                } else {
                    if ($worstCount -gt 0) {
                        Write-Host ("{0} -> {1}: Backlog (max {2} across RFs)" -f $send, $recv, $worstCount)
                    } else {
                        Write-Host ("{0} -> {1}: Backlog/Errors (see details)" -f $send, $recv)
                    }

                    $errorsOrDetails | Select-Object -First 5 | ForEach-Object { Write-Host ("  - {0}" -f $_) }
                    if ($errorsOrDetails.Count -gt 5) { Write-Host "  - ... (more omitted)" }
                }
            }
            else {
                foreach ($rfObj in $rfs) {
                    $rf  = $rfObj.FolderName
                    $res = Invoke-DfsrBacklogStatus -RG $rg -RF $rf -Send $send -Recv $recv

                    if ($res.Status -eq "No Backlog") {
                        Write-Host ("{0} -> {1} [{2}]: No Backlog" -f $send, $recv, $rf)
                    } else {
                        Write-Host ("{0} -> {1} [{2}]: {3}" -f $send, $recv, $rf, $res.Status)
                        if ($res.Detail) { Write-Host ("  - {0}" -f $res.Detail) }
                    }
                }
            }
        }
    }
}
```

!!! example "Example Output"
    You will see output like the following when you run the script.

    ```powershell
    == Replication Group: bunny-lab.io\music\fl studio plugins ==
    LAB-FPS-01 -> LAB-FPS-02: No Backlog
    LAB-FPS-02 -> LAB-FPS-01: No Backlog

    == Replication Group: bunny-lab.io\music\personal music ==
    LAB-FPS-01 -> LAB-FPS-02: No Backlog
    LAB-FPS-02 -> LAB-FPS-01: No Backlog

    == Replication Group: bunny-lab.io\music\shared music ==
    LAB-FPS-01 -> LAB-FPS-02: No Backlog
    LAB-FPS-02 -> LAB-FPS-01: No Backlog

    == Replication Group: bunny-lab.io\projects\coding ==
    LAB-FPS-01 -> LAB-FPS-02: No Backlog
    LAB-FPS-02 -> LAB-FPS-01: No Backlog
    ```

## Related Documentation
- [DFS Deployment](<../../../../deployments/Applications/Files and Collaboration/Windows Server/DFS Namespaces with Replication.md>) — Identify the replication members and folders.
- [Related Files and Collaboration Documentation](<../../../../reference/Applications/Files and Collaboration/index.md>) — Find the connected deployments, procedures, and references for this subject.