force powershell script to stop and retrieve info - powershell

Question

I've got an script that lists files located under C:\ on a list of remote servers:
$Servers=Get-ADComputer -SearchBase $TerminalServersOU -Filter '*' | Sort-Object Name | Select -Exp Name
foreach ($Server in $Servers) {
$Server
#Check first if the terminal server is on
if (Test-Connection $Server -quiet) {
Invoke-Command -ComputerName $Server {
$output=dir C:\
}
}
else {
"`n$Server is disconnected"
}
The script works perfectly fine on all servers except for one called "UKBTH05CTX03". When the script runs on this server, it crashes and never finishes:
UKBTH05CTX01
UKBTH05CTX01 is disconnected
UKBTH05CTX02
Directory: C:\
Mode LastWriteTime Length Name PSComputerName
---- ------------- ------ ---- --------------
d---- 11/09/2014 23:00 inetpub ukbth05ctx02
d---- 11/09/2014 23:00 log ukbth05ctx02
d---- 14/07/2009 04:20 PerfLogs ukbth05ctx02
d-r-- 16/07/2015 15:15 Program Files ukbth05ctx02
d-r-- 15/09/2015 13:01 Program Files (x86) ukbth05ctx02
UKBTH05CTX03
Provider load failure
+ CategoryInfo : InvalidOperation: (:) [Get-WmiObject], ManagementException
+ FullyQualifiedErrorId : GetWMIManagementException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
Provider load failure
+ CategoryInfo : InvalidOperation: (:) [Get-WmiObject], ManagementException
+ FullyQualifiedErrorId : GetWMIManagementException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
d---- 05/10/2014 15:18 inetpub ukbth05ctx03
Provider load failure
+ CategoryInfo : InvalidOperation: (:) [Get-WmiObject], ManagementException
+ FullyQualifiedErrorId : Get WMIManagementException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
I need to be able to show a message like "the script crashed on this server" and finish its execution. It is very important for me to finish its execution and know why it crashed. I don't know how to do it in PowerShell so I am looking for advise.
Thanks to all.

Answer 1

You should use a try/catch block to trap the error, something like this:
$Servers=Get-ADComputer -SearchBase $TerminalServersOU -Filter '*' | Sort-Object Name | Select -Exp Name
foreach ($Server in $Servers) {
$Server
#Check first if the terminal server is on
if (Test-Connection $Server -quiet) {
try
{
Invoke-Command -ComputerName $Server {
$output=dir C:\
}
}
catch
{
Write-Host "the script crashed on server: $server"
}
}
else {
"`n$Server is disconnected"
}
You could get more advanced error handling and actually return back the error received as well if needed, have a look here for more info:
Try Catch Finally and error handling in PowerShell

Answer 2

Pretty sure Test-Connection uses wmi to get Win32_PingStatus. Since you see lots of wmi errors, expand a Try...Catch to include that too.
If all else fails, set $ErrorActionPreference = 'SilentlyContinue' right at the start, and you might at least get some visibility on what is going on to help isolate the issue.