How-To – Check diskspace using PowerShell

Sometimes it’s useful to quickly get an idea of certain usage statistics from a number of servers. Without monitoring and capacity management systems in place it may be difficult to capture information such as disk usage, fragmentation etc.

Rather than logging into each server and manually gather the information, why not automate the task using WMI and PowerShell? The script below will connect to each server in the list ($compList) and determine the free disk space and volume fragmentation.

$compList = "LONDON", "BRISBANE"
$DiskResults = @()
foreach ($computerName in $compList)
  Write-Host $computerName
  $objDisks = Get-WmiObject -Computername $computerName -Class win32_logicaldisk | Where-Object { $_.DriveType -eq 3 }
  ForEach( $disk in $objDisks )
    $diskFragmentation = "Unknown"
      $objDisk = Get-WmiObject -Computername $computerName -Class Win32_Volume -Filter "DriveLetter='$($disk.DeviceID)'"
      $objDefrag = $objDisk.DefragAnalysis()
      $objDefragAnalysis = $objDefrag.DefragAnalysis;
      $diskFragmentation = $objDefragAnalysis.TotalPercentFragmentation
    $ThisVolume = "" | select ServerName,Volume,Capacity,FreeSpace,Fragmentation
    $ThisVolume.ServerName = $computerName
    $ThisVolume.Volume = $disk.DeviceID
    $ThisVolume.Capacity = $([Math]::Round($disk.Size/1073741824,2))
    $ThisVolume.FreeSpace = $([Math]::Round($disk.FreeSpace/1073741824,2))
    $ThisVolume.Fragmentation = $diskFragmentation
    $DiskResults += $ThisVolume
$DiskResults | ft

This could easily be extended to capture windows reliability information using Win32_ReliabilityRecords to determine if servers have crashed recently or other information. Check back for a future post about that.
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Locating PST files on a network

In order to size any mail archiving solution it is important to understand the amount of archive data currently in use. For many companies this is in the form of Outlook Data Files (PST’s). Unforutnately, the only resource Microsoft provide is a VBScript dating back to 2005 on the technet script center.

I decided to have a go at implementing two methods to locate PST files on the network using Powershell, the two options for locating files I came up with are:

  • Enumerate the Outlook settings on client computers to determine PST files loaded on client computers;
  • Use WMI to call the search APIs on remote computers to locate the files;

In testing the two options, using the search APIs via WMI located twice as many files as just relying on the information located in the windows registry. Both scripts will also read the first 11 bytes of the PST file to determine the file format, whether it’s an ANSI or Unicode PST file.

Continue reading Locating PST files on a network

Setting Exchange calendar permissions using Powershell

A trick many people seem to miss is that it’s possible to set a mailbox’s calendar permissions using Powershell. This is achieved using the Add-MailboxFolderPermission and then specifying the folder you want to set permissions on, in this case the calendar.

For example, to set it so that by default everyone has “Reviewer” access to a mailbox:
Add-MailboxFolderPermission -Identity "dave@nwtraders.msft:\Calendar" -User Default -AccessRights Reviewer