All,
I have been struggling on getting some virtual machines to disk punch and getting the right syntax to work.
The below is the powershell script which was posted on "whats up duck". However getting this to run via a scheduled task posed me a number of issues since to get a scheduled task to show on a machine required a reboot (this was done via group policy),
I couldn't get it to display or run any way else. The other alternative would be to do a script which would configure a scheduled task and then remove it, this was just a pain.
Content of Write-ZeroesToFreeSpace.ps1"
<#
.SYNOPSIS
Writes a large file full of zeroes to a volume in order to allow a storage
appliance to reclaim unused space.
.DESCRIPTION
Creates a file called ThinSAN.tmp on the specified volume that fills the
volume up to leave only the percent free value (default is 5%) with zeroes.
This allows a storage appliance that is thin provisioned to mark that drive
space as unused and reclaim the space on the physical disks.
.PARAMETER Root
The folder to create the zeroed out file in. This can be a drive root (c:\)
or a mounted folder (m:\mounteddisk). This must be the root of the mounted
volume, it cannot be an arbitrary folder within a volume.
.PARAMETER PercentFree
A float representing the percentage of total volume space to leave free. The
default is .05 (5%)
.EXAMPLE
PS> Write-ZeroesToFreeSpace -Root "c:\"
This will create a file of all zeroes called c:\ThinSAN.tmp that will fill the
c drive up to 95% of its capacity.
.EXAMPLE
PS> Write-ZeroesToFreeSpace -Root "c:\MountPoints\Volume1" -PercentFree .1
This will create a file of all zeroes called
c:\MountPoints\Volume1\ThinSAN.tmp that will fill up the volume that is
mounted to c:\MountPoints\Volume1 to 90% of its capacity.
.EXAMPLE
PS> Get-WmiObject Win32_Volume -filter "drivetype=3" | Write-ZeroesToFreeSpace
This will get a list of all local disks (type=3) and fill each one up to 95%
of their capacity with zeroes.
.NOTES
You must be running as a user that has permissions to write to the root of the
volume you are running this script against. This requires elevated privileges
using the default Windows permissions on the C drive.
#>
param(
[Parameter(Mandatory=$true,ValueFromPipelineByPropertyName=$true)]
[ValidateNotNullOrEmpty()]
[Alias("Name")]
$Root,
[Parameter(Mandatory=$false)]
[ValidateRange(0,1)]
$PercentFree =.05
)
process{
#Convert the $Root value to a valid WMI filter string
$FixedRoot = ($Root.Trim("\") -replace "\\","\\") + "\\"
$FileName = "ThinSAN.tmp"
$FilePath = Join-Path $Root $FileName
#Check and make sure the file doesn't already exist so we don't clobber someone's data
if( (Test-Path $FilePath) ) {
Write-Error -Message "The file $FilePath already exists, please delete the file and try again"
} else {
#Get a reference to the volume so we can calculate the desired file size later
$Volume = gwmi win32_volume -filter "name='$FixedRoot'"
if($Volume) {
#I have not tested for the optimum IO size ($ArraySize), 64kb is what sdelete.exe uses
$ArraySize = 64kb
#Calculate the amount of space to leave on the disk
$SpaceToLeave = $Volume.Capacity * $PercentFree
#Calculate the file size needed to leave the desired amount of space
$FileSize = $Volume.FreeSpace - $SpacetoLeave
#Create an array of zeroes to write to disk
$ZeroArray = new-object byte[]($ArraySize)
#Open a file stream to our file
$Stream = [io.File]::OpenWrite($FilePath)
#Start a try/finally block so we don't leak file handles if any exceptions occur
try {
#Keep track of how much data we've written to the file
$CurFileSize = 0
while($CurFileSize -lt $FileSize) {
#Write the entire zero array buffer out to the file stream
$Stream.Write($ZeroArray,0, $ZeroArray.Length)
#Increment our file size by the amount of data written to disk
$CurFileSize += $ZeroArray.Length
}
} finally {
#always close our file stream, even if an exception occurred
if($Stream) {
$Stream.Close()
}
#always delete the file if we created it, even if an exception occurred
if( (Test-Path $FilePath) ) {
del $FilePath
}
}
} else {
Write-Error "Unable to locate a volume mounted at $Root"
}
}
}So, PSEXEC then utilising a CMD then powershell to execute this script from a list was the best way. You need to run your CMD with your domain admin account (shift and right click CMD and run as different user) because the issues with PSEXEC is it will try
to use your local rights to create the service which fails and gives you access is denied.
psexec -d -u domain\username @C:\users\%username%\desktop\diskpunch\computers.txt cmd /c "\\dom.ain\NETLOGON\Diskpunch\diskpunch.bat""
(We're putting it in netlogon since we're using it again later)
Then put in your password
((IN YOUR COMPUTERS.TXT JUST LIST THE SERVERS AND PLEASE NOTE THE DOUBLE QUOTES ON THE END))
The batch file has the following
powershell.exe -executionpolicy Bypass -command "Get-WmiObject Win32_Volume -filter drivetype=3 | \\Dom.ain\NETLOGON\diskpunch\Write-ZeroesToFreeSpace.ps1"
This may seem simple for some of you but it really got on my nerves getting the config right so I thought I'd share incase anyone else wants to disk punch their Virtual Infrastructure.
Anyway, hope this helps someone.