As mentioned in my previous post I was recently working with a customer to get started with Exchange Online PowerShell commandlets.  In this post I wanted to follow up and show one example of a difference in output from commandlets in Exchange 2010 on-premises vs. Exchange Online.

Problem

   The customer was interested in getting the size of mailboxes in GB.  For Exchange on-premises this is fairly easy.  A fellow PFE Gary Siepser wrote an article explaining how to accomplish this (click here).  Note that Gary’s script will not work when remoting from a local machine that doesn’t have the Exchange object model installed.  A similar type of scenario exists if you are executing PowerShell against Exchange Online.  The data type for TotalItemSize  being returned (ByteQuantifiedSize) exists in the Exchange namespace.  If the PowerShell session doesn’t have access to that namespace (or hasn’t loaded it) PowerShell works with an approximation of that data type.

   The customer found a sample script on this TechNet article that they attempted to use (minor edits by me to fit on page and remove references to deleted item size.)

Get-Mailbox -ResultSize Unlimited |
   Get-MailboxStatistics |
   Select DisplayName,StorageLimitStatus, `
   @{name="TotalItemSize (MB)"; expression={[math]::Round( `
   ($_.TotalItemSize.Split("(")[1].Split(" ")[0].Replace(",","")/1MB),2)}}, `
   ItemCount |
   Sort "TotalItemSize (MB)" -Descending |
   Export-CSV "C:\My Documents\All Mailboxes.csv" -NoTypeInformation

  The script is targeted to Exchange 2010 but fails for Exchange Online.  In Exchange Online when referencing the TotalItemSize property though it does not have a Split method which ultimately causes the script to fail.

Solution

   A simple solution would be to add a call to the ToString method off of the TotalItemSize property (in bold on line 5 below).

Get-Mailbox -ResultSize Unlimited |
   Get-MailboxStatistics |
   Select DisplayName,StorageLimitStatus, `
   @{name="TotalItemSize (MB)"; expression={[math]::Round( `
   ($_.TotalItemSize.ToString().Split("(")[1].Split(" ")[0].Replace(",","")/1MB),2)}}, `
   ItemCount |
   Sort "TotalItemSize (MB)" -Descending |
   Export-CSV "C:\My Documents\All Mailboxes.csv" -NoTypeInformation

   This fixes the script to run but the numerous string replacements and splits are an eye sore to me.  I attempted to simplify the string manipulation with a regular expression (more info on regular expressions in PowerShell click here).  The result is a workable script that does one nice feature of adding a new member to the mailbox statistics called TotalItemSizeInBytes.  With this member you can then convert into any byte level (KB, MB, GB, etc.) that suits your needs.  You can download the full version of this script below (includes commands to connect to Exchange Online session).

$UserMailboxStats = Get-Mailbox -RecipientTypeDetails UserMailbox `
   -ResultSize Unlimited |
   Get-MailboxStatistics
$UserMailboxStats |
   Add-Member -MemberType ScriptProperty -Name TotalItemSizeInBytes `
   -Value {$this.TotalItemSize -replace "(.*\()|,| [a-z]*\)", ""}
$UserMailboxStats |
   Select-Object DisplayName,@{Name="TotalItemSize (GB)"; `
   Expression={[math]::Round($_.TotalItemSizeInBytes/1GB,2)}}

Conclusion

   Moving from on-premises to the cloud with PowerShell (and PowerShell remoting in general) can sometimes present some new challenges due to what you have access to.  This means that you must always test your code / scripts.  I still believe that not having to physically RDP to a server is a huge gain over some of the small hurdles you may encounter during the transition.  Scripting is the future of administration and makes you more valuable.  Hopefully this script and the concepts presented help you be a better admin / developer.

      -Frog Out

Links

The Get-MailboxStatistics Cmdlet, the TotalitemSize Property, and that pesky little “b”

http://blogs.technet.com/b/gary/archive/2010/02/20/the-get-mailboxstatistics-cmdlet-the-totalitemsize-property-and-that-pesky-little-b.aspx

View Mailbox Sizes and Mailbox Quotas Using Windows PowerShell

http://technet.microsoft.com/en-us/exchangelabshelp/gg576861#ViewAllMailboxes

Regular Expressions with Windows PowerShell

http://www.regular-expressions.info/powershell.html

“I don’t always test my code…” image

http://blogs.pinkelephant.com/images/uploads/conferences/I-dont-always-test-my-code-But-when-I-do-I-do-it-in-production.jpg

The One Thing: Brian Jackett and SharePoint 2010

http://www.youtube.com/watch?v=Sg_h66HMP9o