The most efficient way for
PowerShell to cure a hung service is with the verb restart.
Restart-Service xyz is just simpler and more efficient than stop-Service
xyz, followed by start-Service xyz. If you are new to PowerShell
Restart-Service, then I suggest that
you begin with my Get-Service page.
The service which benefits most from Restart-Service is, "Spooler".
The reason being the printer gives more trouble than any other piece of hardware, and
often restarting the Spooler cures the problem. The inferior, but ruthless method of curing such printer
jams is to reboot the computer. When the the computer is also a fileserver, this
technique is undesirable.
Production Script
All you really need is
this simple command:
# PowerShell Restart-Service example Restart-Service "Spooler"
Note 1: You can change "Spooler" to the name of
another service. To list services see
PowerShell's Get-Service
Comprehensive Restart-Service Script
# PowerShell cmdlet to restart the Spooler service $SrvName =
"Spooler" $ServicePrior = Get-Service $SrvName "$srvName is " +
$servicePrior.status Set-Service $SrvName -startuptype manual
Restart-Service $srvName $ServiceAfter = Get-Service $SrvName
"$SrvName is now " + $ServiceAfter.status Set-Service $SrvName
-startuptype automatic
Learning Points
Note 2: My biggest fear is that in a production script I will misspell the name of the service. Thus, check for success by observing this system message:
WARNING: Waiting
for service 'Print Spooler (Spooler)' to finish starting...
Note 3: There will be variations depending on
which operating system you are using.
Encouraging computers to sleep when not in use is a great idea -
until you are away from your desk and need a file on that remote sleeping machine!
Wake-On-LAN really will save you that long walk to awaken a hibernating
machine; however my reason for encouraging you to download this utility is
just because it's so much fun sending those 'Magic Packets'. As Wake-On-LAN (WOL) is free, see
if I am right, and you get a kick from arousing those sleeping machines.
WOL also has business uses for example, wakening machines so that they can have
their patches applied.
What's in a Name? What do these groups of services have in common?
Group A Alerter,
Messenger, WebClient
Group B Print Spooler, Telnet, Telephony and Windows Time
More importantly, why won't the PowerShell's service family interact with Group B?
The Answer: Some
services have a 'Display Name' which differs from their 'Service Name', for example Telnet and Tlnsvr. How did I find this out? When I tried to start 'Telnet', or 'Print Spooler', nothing happened.
Yet if I had a manual walk-through in the Service GUI, no problem. Then I ran Get-Service * and observed the two columns, Name and also Display Name. What threw me into confusion was Group A, where
both names are the same.
Just to emphasise, if you wish to use the name
'Print Spooler', you need to specify the property -DisplayName.
# PowerShell Restart-Service example using displayName Restart-Service
-displayName "Print Spooler"
Note 4: You could research the names and
displayNames with Get-Service.
In Windows Server 2003 days I choose the Alerter service for testing, partly because it's relatively harmless service, and partly because its name is near the top of the list!
However, since it's been removed from Windows 7 and Server 2008 does I
have
choosen PLA (Performance Logs and Alerts) to test PowerShell's service
cmdlets.
Preliminary Script
Let us check the service's status, and also let us 'warm up' with Get-Service before we employ other members of the service family.
# PowerShell cmdlet to check a service's status $srvName = "PLA" $servicePrior = Get-Service $srvName $srvName + " is now " + $servicePrior.status
Learning Points
Note 5: I have decided to introduce the variable $srvName to hold the value of the service.
Hopefully this will emphasise the name of the service, and prompt
you to change it as necessary for your project.
Note 6: Observe how I mix the ''literal phrases'' with the
$variables and properties to produce a meaningful output.
Guy Recommends: Solarwinds' Log & Event Management Tool
LEM will alert you to problems such as when a key
application on a particular server is unavailable. It can also
detect when services have stopped, or if there is a
network latency problem. Perhaps this log and event management
tool's most interesting ability is to take corrective action, for
example by
restarting services, or isolating the source of a maleware attack.
Yet perhaps the killer reason why people
use LEM is for its
compliance capability, with a little help from you, it will ensure that your organization complies with industry
standards such as CISP or FERPA. LEM is a really smart
application that can make correlations between data in different logs,
then use its built-in logic to take corrective action, to restart services,
or thwart potential security breaches.
Windows 7 and Server 2008 do not have an Alerter service, this is
why I now use PLA (Performance Logs and Alerts) to test PowerShell's
start-Service.
# PowerShell cmdlet to start a named service $srvName = "PLA" $servicePrior = Get-Service $srvName "$srvName is now " + $servicePrior.status
Set-Service $srvName -startuptype manual Start-Service $srvName $serviceAfter =
Get-Service $srvName "$srvName is now " + $serviceAfter.status
Learning Points
Note 7: Observe how the speech marks are slightly different in this script
compared with the previous: "$srvName is now " + $servicePrior.status
compared with $srvName + " is now " + $servicePrior.status
My
points are: a) Experiment yourself. b) To some extent, these learning scripts leave traces of my thinking process.
Note 8: I prepared the above script to help you appreciate the factors needed to control a Windows Service. It also reflects my thinking process of how I learn about a
command. On the other hand, for a production script you could take a much more ruthless approach and simplify the script thus:
Guy Recommends: A Free Trial of the Network Performance Monitor
(NPM)
Solarwinds'
Orion performance monitor
will help you discover what's happening on your network. This
utility will also guide you through troubleshooting; the dashboard will
indicate whether the root cause is a broken link, faulty equipment or
resource overload.
Perhaps the NPM's best feature is the way it suggests solutions to network
problems. Its
second best feature is the ability to monitor the health of individual VMWare
virtual machines. If you are interested in troubleshooting, and creating network maps, then I recommend that you take advantage of Solarwinds' offer.
In real life, you may want a script which ensures that services such as: Telnet, Messenger and Routing and Remote Access are Stopped. Just for testing, you may need a script which reverses
start-Service, just to be sure that it really is working as designed. Either way, here is a script which stops the service defined by $srvName.
# PowerShell cmdlet to stop the Plug & Play service $srvName = "PLA" $servicePrior = Get-Service $srvName "$srvName is now " + $servicePrior.status stop-Service $srvName $serviceAfter = Get-Service $srvName set-Service $srvName
-startuptype disabled "$srvName is now " + $serviceAfter.status
Learning Points
Note 9: Observe how this script is the mirror image of the Start-Service script. It even disables the service once it has stopped. If you remember, when
Example 1 wanted to start a service, it must first make sure the -startuptype is set to manual.
The Service Family (Each member has a different verb)
Clear-Host Get-Command -noun Service
Get-Service: Useful for listing
the services Set-Service:
Crucial parameter -startuptype
Start-Service: The verb 'start' says it all Stop-Service: Handy for
scripts which prevent unwanted services running e.g. Telnet Restart-Service: A nice
touch by the creator's of PowerShell; this cmdlet removes the need to
explicitly stop then start the service.
Remoting with PowerShell Service
One aspect of remoting in PowerShell v 2.0 is simply to append
-computerName xyz to the command that you ran on the local machine.
For further research try:
Clear-Host Get-Command | where { $_.parameters.keys -contains
"ComputerName"}
Surprise! Get-Service is amongst the cmdlets that support
remoting, but stop, start and restart-Service are not on the list.
More bad news, stop, start and restart-Service really don't work on
network machines. Thus you have to employ different techniques
such as Get-WmiObject and InvokeMethod. Alternatively, you could
enter-PSSession and then run restart-Service as if you were on the local
machine. However, to get that working you have to first
install and setup WinRM
If your mission is to master the start-Service command, commence with Get-Service. Once you have mastered
the rhythm of the Get-Service verb-noun pair, move on to the Start, Stop, and restart-Service family of PowerShell commands. For scripting purposes, make sure that you use the true Service Name, and avoid
the Service's Display Name. A final piece of advice, open the Service GUI so that you can double-check that what your script is doing is what you intended.
If you like this page then please share it with your friends
See more PowerShell examples of process and service
Please email me if you have a better example script. Also please report any factual mistakes, grammatical errors or broken links, I will be happy to correct the fault.
Windows Management Instrumentation (WMI) is one of the hidden
treasures of Microsoft operating systems.
Fortunately, Solarwinds
have created the
Free WMI Monitor so that you can actually see and understand these gems of
performance information. Take the guess work out of which
WMI counters to use for applications like Microsoft Active Directory,
SQL or Exchange Server.
