Create a Zero’d out File with Powershell

When sql server adds space to a transaction log file (or creates the transaction log file) it needs to zero-out said file.  Whilst zeroing out the file Sql Server is unfortunately read-only.  Hence why you need to be careful in setting reasonable transaction log growth sizes.  I wanted to get a quick fix on how long a particularly old system took to create a file and zero it out, hence this script.

$start = get-date
$File = 'c:\fileToCreate.txt'

if(Test-Path $File){
    Remove-Item $File -Force
$arrSize= 64kb
$fileSize= 1GB
$buffer = new-object byte[]($arrSize)
$stream = [io.File]::OpenWrite($File)

    $size = 0
    while($size -lt $fileSize){
        $stream.Write($buffer, 0, $buffer.Length);
        $size += $buffer.Length;
    $ts = New-TimeSpan -Start $start -End (Get-Date)

2 thoughts on “Create a Zero’d out File with Powershell

  1. You have:
    $File = ‘c:\fileToCreate.txt’
    but you open using:
    $stream = [io.File]::OpenWrite($FilePath)

    $FilePath needs to be $File or $File needs to be $FilePath for this to work.

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