If you’ve ever had to put a large number of 2008+ Windows Terminal/Remote Desktop servers in “drain mode” using the gui admin tool, you know it can be slow and tedious.  Faced with doing this on a Saturday night for about 30 servers I decided to make life a little quicker and easier by building a powershell script.   While my long term goal is to figure out how to drain an entire farm, for now I’m pretty satisfied to be able to do it from PowerShell pretty quickly.

There are two scripts.  Drain-RDserver.ps1 and Undrain-RDserver.ps1. Both require a single parameter “-RDserver” followed by the server name.  Drain changes the “User logon mode” to “Allow reconnections, but prevent new logons.” This could be changed to the “Allow reconnections, but prevent new logons until the server is restarted” by modifying the script.   Undrain puts the server back in “Allow all connections” mode.

Big thanks to SourceDaddy’s article which got me started on the right path. (http://sourcedaddy.com/windows-7/preparing-server-maintenance.html)

Here is the code:

###Drain-RDServer
# Input computer name
param (
[string]$RDServer = $(throw "-RDserver is required")
)
$RDSH = Get-WmiObject -Class "Win32_TerminalServiceSetting" -Namespace "root\CIMV2\terminalservices" -ComputerName $RDServerdra -Authentication PacketPrivacy -Impersonation Impersonate
$RDSH.SessionBrokerDrainMode=1
$RDSH.put() > $null
Write-Host "$RDServer is set to:"
switch ($RDSH.SessionBrokerDrainMode)
{
0 {"Allow all connections."}
1 {"Allow incoming reconnections but prohibit new connections."}
2 {"Allow incoming reconnections but until reboot prohibit new connections."}
default {"The user logon state cannot be determined."}
}

###Undrain-RDServer
# Input computer name
param (
[string]$RDServer = $(throw "-RDserver is required")
)
$RDSH = Get-WmiObject -Class "Win32_TerminalServiceSetting" -Namespace "root\CIMV2\terminalservices" -ComputerName $RDServer -Authentication PacketPrivacy -Impersonation Impersonate
$RDSH.SessionBrokerDrainMode=0
$RDSH.put() > $null
Write-Host "$RDServer is set to:"
switch ($RDSH.SessionBrokerDrainMode)
{
0 {"Allow all connections."}
1 {"Allow incoming reconnections but prohibit new connections."}
2 {"Allow incoming reconnections but until reboot prohibit new connections."}
default {"The user logon state cannot be determined."}
}

And here is a link to the scripts in a zip file.