List Sever Reboot Times

I was recently working on a Windows Server in my office when I noticed it had not been rebooted in a while. That got me to thinking, how many other servers in my environment had gotten in under the radar and were in need of a reboot. So, I decided to try my hand at writing another PowerShell Script. I started with a function called Get-RebootTime which is part of a module called BSonPosh. This module was created by Brandon Shell who is a MVP and who has his own blog at http://bsonposh.com.

What I was looking to do was to have a list of the servers I wanted to check on a regular basis and have it automatically check each server and write the results to a csv file. That way I could review the file at my leisure and sort it by oldest reboot date.

So, I set about creating my script.

First I created a variable to contain my list of servers.

$Servers = "DC1", "FS1", "RPTS1", "SQL1"

Then I wrote a ForEach statement to run a cmd for each item in the $Servers list.

ForEach ($Computer in $Servers) { Get-RebootTime -ComputerName $Computer -Last }

When I ran this in my PowerShell editor it produced the desired results but in a simple list.

This was great but the output was on the screen and not in a file that I could look at later and it wasn’t in a format I could manipulate. So, next step was to look into outputting the info into a file.

I tried using the Export-Csv cmdlet like this

ForEach ($Computer in $Servers) { Get-RebootTime -ComputerName $Computer –Last | Export-Csv ‘C:\Greg\boottimes.csv’ -notype}

This worked, or so I thought, but in reality all it did was each time overwrite the same file with an entry.  So that when I viewed the file it only showed the LAST server that the script queried.

That wouldn’t do…

So, I started looking into how to get the results of each Get-RebootTime cmd into an array so I could later output the array into csv. 

What I came up with was this:

First I created an empty array called $results to hold all my output.

$results = @()

I also created a variable for the path and name of the output file.

$outputFile = ‘C:\Greg\boottimes.csv’

Then I changed my script to use New-Object cmdlet to create a new object called $result and using the Add-Member cmdlet I was able to add members to my object in the form of the values of the server name and the reboot time each time I looped through. Then I would take the object and add it to my $results array. When the loop was completed I could then use the Export-Csv cmdlet to output $results all at once into a csv file.

Here is what the finished script looked like:

# ServerBootTimes.ps1
# Written by Greg Caporale Febrary 28, 2012
#
# Determines the last date a list of computers was rebooted
# Exports the results to a csv file.
#
# Adjust the server list accordingly
# Adjust the path and file name for the output file to your needs
$results = @()
$Servers = "DC1", "FS1", "RPTS1", "SQL1"
$outputFile = ‘C:\Greg\boottimes.csv’
ForEach ($Computer in $Servers) {
$result = New-Object psObject
$result | Add-Member -MemberType NoteProperty -Name ‘Computer Name’ -Value $Computer
$rbttime = Get-RebootTime -ComputerName $Computer -Last | select -ExpandProperty RebootTime
$result | Add-Member -MemberType NoteProperty -Name ‘Last Reboot’ -Value $rbttime
$results += $result
}
$results | Export-Csv $outputFile -notype

SUCCESS!!  I had my csv file and was able to see all the servers and their reboot times.  This was a great exercise for me and it also gave me a nice little utility script that I could have handy or even schedule to run automatically so I always know how long its been between reboots of my servers.