param(
[int]$IntervalSec = 10,
[int]$TopN = 10,
[string]$OutPath = ("logs/memwatch-{0}.csv" -f (Get-Date -Format "yyyyMMdd-HHmmss"))
)
$ErrorActionPreference = 'SilentlyContinue'
function GB([double]$b) { [math]::Round($b / 1GB, 2) }
function GetCounterSafe([string]$path) {
try {
$c = Get-Counter $path -ErrorAction Stop
if ($c.CounterSamples -and $c.CounterSamples.Count -gt 0) { return $c.CounterSamples[0].CookedValue }
} catch { }
return $null
}
function GetCounterSafeOrZero([string]$path) {
$v = GetCounterSafe $path
if ($null -eq $v) { return 0 } else { return $v }
}
# Ensure output directory exists
$dir = Split-Path -Parent $OutPath
if (-not [string]::IsNullOrWhiteSpace($dir)) {
New-Item -Path $dir -ItemType Directory -Force | Out-Null
}
Write-Host "Starting memwatch. Interval: $IntervalSec s, TopN: $TopN, Output: $OutPath"
Write-Host "Press Ctrl+C to stop."
# Helper to build a record with dynamic top-N fields and export as CSV (append after first write)
function Write-Record {
param([hashtable]$h, [string]$path)
$obj = [PSCustomObject]$h
if (-not (Test-Path -Path $path)) {
$obj | Export-Csv -Path $path -NoTypeInformation
} else {
$obj | Export-Csv -Path $path -Append -NoTypeInformation
}
}
while ($true) {
try {
$ts = Get-Date -Format o
# System snapshot
$os = Get-CimInstance Win32_OperatingSystem
$totalGB = [math]::Round($os.TotalVisibleMemorySize / 1MB, 2)
$freeGB = [math]::Round($os.FreePhysicalMemory / 1MB, 2)
$commit = GetCounterSafeOrZero '\Memory\Committed Bytes'
$commitLimit = GetCounterSafeOrZero '\Memory\Commit Limit'
$np = GetCounterSafeOrZero '\Memory\Pool Nonpaged Bytes'
$pp = GetCounterSafeOrZero '\Memory\Pool Paged Bytes'
$cache = GetCounterSafeOrZero '\Memory\Cache Bytes'
$standbyNorm = GetCounterSafeOrZero '\Memory\Standby Cache Normal Priority Bytes'
$standbyRes = GetCounterSafeOrZero '\Memory\Standby Cache Reserve Bytes'
$standbyCore = GetCounterSafeOrZero '\Memory\Standby Cache Core Bytes'
$compressedPg = GetCounterSafeOrZero '\Memory\Compressed Page Count'
$compressedB = $compressedPg * 4096
$pagefilePct = GetCounterSafeOrZero '\Paging File(_Total)\% Usage'
$sumPrivate = (Get-Process | Measure-Object -Property PrivateMemorySize64 -Sum).Sum
$sumWS = (Get-Process | Measure-Object -Property WorkingSet64 -Sum).Sum
# Kernel-ish approximation and unattributed commit delta
$pt = GetCounterSafeOrZero '\Memory\Page Table Bytes'
$sysCodeTotal = GetCounterSafeOrZero '\Memory\System Code Total Bytes'
$sysDriverResident = GetCounterSafeOrZero '\Memory\System Driver Resident Bytes'
$kernelCommitApprox = $np + $pp + $pt + $sysDriverResident + $sysCodeTotal
$delta = $commit - ($sumPrivate + $kernelCommitApprox)
# Top processes by Private Bytes
$top = Get-Process | Select-Object Name, Id,
@{Name='PrivateMB'; Expression={[math]::Round($_.PrivateMemorySize64 / 1MB, 1)}},
@{Name='WSMB'; Expression={[math]::Round($_.WorkingSet64 / 1MB, 1)}} |
Sort-Object PrivateMB -Descending | Select-Object -First $TopN
if ($null -eq $top) { $top = @() }
# Compose CSV row
$commitPct = if ($commitLimit -gt 0) { [math]::Round(($commit / $commitLimit) * 100, 1) } else { 0 }
$row = [ordered]@{
Timestamp = $ts
TotalGB = $totalGB
FreeGB = $freeGB
CommitGB = (GB $commit)
CommitLimitGB = (GB $commitLimit)
CommitPct = $commitPct
PagefileUsagePct = [math]::Round($pagefilePct, 1)
NonpagedGB = (GB $np)
PagedGB = (GB $pp)
CacheGB = (GB $cache)
StandbyGB = (GB ($standbyNorm + $standbyRes + $standbyCore))
CompressionGB = (GB $compressedB)
SumPrivateGB = (GB $sumPrivate)
SumWorkingSetGB = (GB $sumWS)
KernelApproxGB = (GB $kernelCommitApprox)
DeltaCommitGB = (GB $delta)
}
# Add dynamic top-N columns
for ($i = 0; $i -lt $TopN; $i++) {
if ($i -lt $top.Count) {
$p = $top[$i]
$row["Top$($i+1)Name"] = $p.Name
$row["Top$($i+1)Pid"] = $p.Id
$row["Top$($i+1)PrivMB"] = $p.PrivateMB
$row["Top$($i+1)WSMB"] = $p.WSMB
} else {
$row["Top$($i+1)Name"] = $null
$row["Top$($i+1)Pid"] = $null
$row["Top$($i+1)PrivMB"] = $null
$row["Top$($i+1)WSMB"] = $null
}
}
# Export
Write-Record -h $row -path $OutPath
# Console status
$status = ("[{0}] Commit {1:N2}/{2:N2} GB ({3:N1}%), Free {4} GB, Standby {5} GB, Delta {6:N2} GB" -f `
$ts, (GB $commit), (GB $commitLimit), $commitPct, $freeGB, (GB ($standbyNorm + $standbyRes + $standbyCore)), (GB $delta))
if (($commit / $commitLimit) -ge 0.95) {
Write-Warning $status
} else {
Write-Host $status
}
} catch {
Write-Warning ("memwatch iteration error: {0}" -f $_.Exception.Message)
}
Start-Sleep -Seconds $IntervalSec
}
