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

    Fault : Data Deduplication jobs fail or stop reclaiming space
    Fix   : Check eligibility, then the schedule
    Source: https://jbtecwiz.com/support/srv-sto-dedup

    Run as     : Elevated PowerShell
    Expect     : 45 minutes
    Risk       : low
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    Savings are not what is expected.

    HOW TO UNDO IT
    Set-DedupVolume can restore the previous settings. Start-DedupJob -Type
    Unoptimization reverses deduplication entirely, given enough free space.

    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 6"
    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 '  Data Deduplication jobs fail or stop reclaiming space' -ForegroundColor White
Write-Host '  Check eligibility, then the schedule' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: low   Reversible   45 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 status and what has actually been optimised.' -Command {
    Get-DedupStatus | Format-List Volume,Capacity,SavedSpace,SavingsRate,OptimizedFilesCount,InPolicyFilesCount,LastOptimizationResult
}

Invoke-Step -Number 2 -Do 'Compare InPolicyFilesCount against the total. A low number means the files are not eligible, not that deduplication is failing.' -Why 'The default minimum file age is three days, and several file types are excluded outright. A volume of files written yesterday will show zero savings and nothing is wrong with it.' -Command {
    Get-DedupVolume | Format-List Volume,MinimumFileAgeDays,ExcludeFileType,ExcludeFolder,UsageType
}

Invoke-Step -Number 3 -Do 'Adjust the minimum age if the workload justifies it.' -Command {
    Set-DedupVolume -Volume E: -MinimumFileAgeDays 1
}

Invoke-Step -Number 4 -Do 'Check the job schedule and whether jobs are completing inside their window.' -Command {
    Get-DedupSchedule | Format-Table Name,Type,Enabled,Days,Start,DurationHours,Memory
    Get-DedupJob | Format-Table Type,Volume,Progress,State
}

Invoke-Step -Number 5 -Do 'Give the optimisation job more memory and a longer window on a large volume.' -Command {
    Set-DedupSchedule -Name BackgroundOptimization -Memory 50 -DurationHours 9 -Priority Normal
}

Invoke-Step -Number 6 -Do 'Run garbage collection and scrubbing manually to reclaim space from deleted files.' -Why 'Deleting a file does not return its space immediately -- the chunks remain until garbage collection runs. A volume that has had a large deletion will not show the space back until this completes.' -Command {
    Start-DedupJob -Volume E: -Type GarbageCollection -Full
    Start-DedupJob -Volume E: -Type Scrubbing
}

Write-Rule "  Confirm it worked"
Show-Prose 'Get-DedupStatus shows a rising savings rate and the last job result is success.' 'White'
Write-Host ''
if (-not $DryRun) {
    Get-DedupStatus | Format-List Volume,SavingsRate,LastOptimizationResult,LastGarbageCollectionResult
}

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-sto-dedup' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Set-DedupVolume can restore the previous settings. Start-DedupJob -Type Unoptimization reverses deduplication entirely, given enough free space.' 'DarkGray'
Write-Rule