http://www.mikepfeiffer.net/2010/05/quick-tip-how-to-check-exchange-database-size-with-powershell/
Get-MailboxDatabase -Status | select Name,DatabaseSize
Error trying to remove mailbox database.
http://blog.chrislehr.com/2009/10/exchange-2010-what-is-arbitration.htm
Get-ADServerSettings | fl *view*
Set-ADServerSettings -ViewEntireForest $true
Get-ADServerSettings | fl *view*
Get-Mailbox -Arbitration -Database mdb1
Get-Mailbox -Arbitration -Database mdb1 | New-MoveRequest -TargetDatabase "MDB3"