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

    Fault : Cluster Shared Volume in redirected access -- everything slows down
    Fix   : Restore the node's direct path to the storage
    Source: https://jbtecwiz.com/support/srv-clu-csv-redirected

    Run as     : Elevated PowerShell on the affected node
    Expect     : 60 minutes
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    One node is redirected.

    HOW TO UNDO IT
    Set-ClusterSharedVolumeState -State FileSystemRedirected restores
    redirection if needed for maintenance.

    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

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 '  Cluster Shared Volume in redirected access -- everything slows down' -ForegroundColor White
Write-Host '  Restore the node''s direct path to the storage' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   60 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 'Confirm which volumes and nodes are affected.' -Why 'RedirectedIOReason names the cause directly -- NoDiskConnectivity, UserRequest, BlockRedirectedIOdueToFileSystemFilter and so on. That one field decides which of the fixes applies.' -Command {
    Get-ClusterSharedVolume | Format-Table Name,State,OwnerNode
    Get-ClusterSharedVolumeState | Format-Table Name,Node,StateInfo,VolumeFriendlyName,RedirectedIOReason
}

Invoke-Step -Number 2 -Do 'For NoDiskConnectivity, check the storage paths on that node.' -Command {
    Get-Disk | Format-Table Number,FriendlyName,OperationalStatus,BusType
    mpclaim -s -d
    Get-InitiatorPort | Format-Table NodeAddress,ConnectionType,OperationalStatus
}

Invoke-Step -Number 3 -Do 'Check the SAN zoning and the HBA or iSCSI sessions from that node specifically.' -Manual

Invoke-Step -Number 4 -Do 'Turn redirection off once the path is restored.' -Command {
    Get-ClusterSharedVolume 'Cluster Disk 1' | Set-ClusterSharedVolumeState -State Normal
}

Invoke-Step -Number 5 -Do 'If it was set manually for maintenance and forgotten, that is the whole cause.' -Command {
    Get-ClusterSharedVolumeState | Where-Object StateInfo -ne 'Direct' | Format-List
}

Write-Rule "  Confirm it worked"
Show-Prose 'Every node reports Direct I/O for the volume.' 'White'
Write-Host ''
if (-not $DryRun) {
    Get-ClusterSharedVolumeState | Format-Table Name,Node,StateInfo
}

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-csv-redirected' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Set-ClusterSharedVolumeState -State FileSystemRedirected restores redirection if needed for maintenance.' 'DarkGray'
Write-Rule