| If you followed the TechNet documentation for Set-SPContentDatabase and try to take SharePoint content databases offline by running Set-SPContentDatabase –Status Offline you will be really disappointed to know that it just does not work. If you look at the TechNet documentation, the type associated with Status is Microsoft.SharePoint.Administration.SPObjectStatus, valid values are “Online”, “Disabled”, “Offline”, “Unprovisioning”, “Provisioning”, “Upgrading” See this link for more information Unfortunately passing none of the above values work. So I decided to look into the source of manage content database settings page by doing a view source in browser 
What I found in view source is valid values for Database Status is 0 and 1 as shown in screenshot below. 
So to Take Content Database Offline you have to run the following script Get-SPContentDatabase “{replace with name of content database}” | Set-SPContentDatabase –Status 1 Bring Content Database Back Online Get-SPContentDatabase “{replace with name of content database}” | Set-SPContentDatabase –Status 0 Cheers, </Ram> |