#Requires -Version 5.1
<#
    JbTecWiz Support Centre -- generated fix script

    Fault : The cluster will not start -- quorum lost, event 1177
    Fix   : Restore or replace the witness
    Source: https://jbtecwiz.com/support/srv-clu-quorum

    Run as     : Elevated PowerShell on a node
    Expect     : 40 minutes
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    The witness is the missing vote.

    HOW TO UNDO IT
    Set-ClusterQuorum -NodeMajority returns to the previous model.

    This script walks the fix one step at a time and asks before each
    one. Steps with no command are things you do yourself -- it prints
    those and waits. Run with -DryRun to print without executing.

    --------------------------------------------------------------------
    NO WARRANTY - USE AT YOUR OWN RISK

    This script is provided by JbTecWiz as-is and with no warranty of any
    kind, express or implied. You run it entirely at your own risk.

    JbTecWiz accepts no liability for any loss or damage arising from its
    use, including but not limited to data loss, downtime, or configuration
    changes that turn out to be wrong for your system.

    You are responsible for reading this script before running it, for
    satisfying yourself that it suits the machine in front of you, and for
    having a working backup first. Some steps cannot be undone.
    --------------------------------------------------------------------
#>

[CmdletBinding()]
param(
    # Print every step and command without running anything.
    [switch]$DryRun,
    # Do not ask before each step. Read the script first if you use this.
    [switch]$Unattended
)

$ErrorActionPreference = 'Stop'
$script:Failed = 0

# - THIS SCRIPT WILL NOT RUN UNTIL YOU EDIT IT -
# The commands below contain values only you can supply. Search the
# script for each one, replace it, then delete this block.
$script:MustEdit = @(
    '\\fileserver\clusterwitness'   # a placeholder network path
)
if ($script:MustEdit.Count) {
    Write-Host ""
    Write-Host '  This script needs editing before it can run.' -ForegroundColor Yellow
    Write-Host '  Replace each of these with a real value:' -ForegroundColor Yellow
    $script:MustEdit | ForEach-Object { Write-Host ("    " + $_) -ForegroundColor Yellow }
    Write-Host ""
    Write-Host '  Then delete the $script:MustEdit block near the top.'
    Write-Host ""
    exit 2
}

function Write-Rule { param([string]$Text)
    Write-Host ''
    Write-Host ('-' * 70) -ForegroundColor DarkGray
    if ($Text) { Write-Host $Text -ForegroundColor Cyan }
}

function Show-Prose { param([string]$Text, [string]$Colour = "Gray")
    if (-not $Text) { return }
    $words = $Text -split "\s+"; $line = "  "
    foreach ($w in $words) {
        if (($line.Length + $w.Length) -gt 74) { Write-Host $line -ForegroundColor $Colour; $line = "  " }
        $line += "$w "
    }
    if ($line.Trim()) { Write-Host $line -ForegroundColor $Colour }
}

function Invoke-Step {
    param(
        [int]$Number, [string]$Do, [string]$Why,
        [scriptblock]$Command, [switch]$Manual, [string]$Shell = "powershell"
    )
    Write-Rule "  Step $Number of 5"
    Show-Prose $Do "White"
    if ($Why) { Write-Host ""; Show-Prose $Why "DarkGray" }

    if ($Manual) {
        Write-Host ''
        Write-Host '  -> Do this yourself, then press Enter to carry on.' -ForegroundColor Yellow
        if (-not $Unattended -and -not $DryRun) { [void](Read-Host) }
        return
    }

    Write-Host ''
    foreach ($l in ($Command.ToString().Trim() -split "`n")) {
        Write-Host ("    " + $l.Trim()) -ForegroundColor Green
    }
    Write-Host ''

    if ($DryRun) { Write-Host "  (dry run -- not executed)" -ForegroundColor DarkGray; return }
    if (-not $Unattended) {
        $a = Read-Host "  Run this step? [Y]es / [S]kip / [Q]uit"
        if ($a -match "^[Qq]") { Write-Host "  Stopped at your request."; exit 0 }
        if ($a -match "^[Ss]") { Write-Host "  Skipped." -ForegroundColor DarkGray; return }
    }
    try { & $Command }
    catch {
        $script:Failed++
        Write-Host ("  Step $Number failed: " + $_.Exception.Message) -ForegroundColor Red
        Show-Prose "The rest of the fix may depend on this. Read the write-up before carrying on." "Red"
        if (-not $Unattended) {
            $c = Read-Host "  Carry on anyway? [y/N]"
            if ($c -notmatch "^[Yy]") { exit 1 }
        }
    }
}

Write-Rule
Write-Host '  The cluster will not start -- quorum lost, event 1177' -ForegroundColor White
Write-Host '  Restore or replace the witness' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   40 minutes'
Write-Host ''
Show-Prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.' 'DarkYellow'
Write-Rule

if (-not $Unattended -and -not $DryRun) {
    $go = Read-Host '  Ready? [y/N]'
    if ($go -notmatch "^[Yy]") { Write-Host "  Nothing was changed."; exit 0 }
}

Invoke-Step -Number 1 -Do 'Check the current quorum configuration and node votes.' -Command {
    Get-ClusterQuorum | Format-List Cluster,QuorumResource,QuorumType
    Get-ClusterNode | Format-Table Name,State,NodeWeight,DynamicWeight
}

Invoke-Step -Number 2 -Do 'If the witness is a file share, check the share is reachable and the cluster name object still has permission on it.' -Why 'The cluster name object needs full control on the witness share. A file server rebuild or a permissions tidy-up removes it, and the cluster carries on with one fewer vote until the day a node reboots.' -Command {
    Test-Path '\\fileserver\clusterwitness'
    Get-SmbShareAccess -Name clusterwitness -CimSession fileserver
}

Invoke-Step -Number 3 -Do 'Reconfigure the witness.' -Command {
    Set-ClusterQuorum -FileShareWitness '\\fileserver\clusterwitness'
}

Invoke-Step -Number 4 -Do 'A cloud witness is a better choice for a two-node cluster with no reliable third location.' -Command {
    Set-ClusterQuorum -CloudWitness -AccountName 'storageaccount' -AccessKey 'key'
}

Invoke-Step -Number 5 -Do 'Confirm dynamic quorum is enabled, which lets the cluster survive sequential node failures.' -Command {
    (Get-Cluster).DynamicQuorum
    (Get-Cluster).WitnessDynamicWeight
}

Write-Rule "  Confirm it worked"
Show-Prose 'The witness has a vote and the cluster reports quorum healthy.' 'White'
Write-Host ''
if (-not $DryRun) {
    Get-ClusterQuorum | Format-List
    Get-ClusterNode | Format-Table Name,State,NodeWeight
}

Write-Rule
if ($script:Failed -gt 0) {
    Write-Host ("  Finished with " + $script:Failed + " failed step(s).") -ForegroundColor Yellow
    Show-Prose 'Read the full write-up at https://jbtecwiz.com/support/srv-clu-quorum' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Set-ClusterQuorum -NodeMajority returns to the previous model.' 'DarkGray'
Write-Rule