I love a powershell challenge, and last week a colleague of mine asked me for assistance in getting the uptime of vmware hosts. My initial response did the trick:
Get-View -ViewType hostsystem -Property name,runtime.boottime | Select-Object Name, @{N="UptimeDays"; E={((((get-date) - ($_.runtime).BootTime).TotalDays).Tostring()).Substring(0,5)}}
However, I wasn’t completely satisfied by the the output or the ease of use.
So today I went back and rewrote the code and made a function of it.
Instead of using the ToString and Substring methods I went for the built-in class Math, which has a method called Round. You can learn more about the Math class here: http://www.madwithpowershell.com/2013/10/math-in-powershell.html
Anyways, here’s the function I came up with:
function Get-VMHostUptime
{
[CmdletBinding()]
Param (
[Parameter(ValueFromPipeline=$True,ValueFromPipelineByPropertyName=$True)][Alias('Name')][string]$VMHosts,
[string]$Cluster
)
Process{
If ($VMHosts) {
foreach ($VMHost in $VMHosts) {Get-View -ViewType hostsystem -Property name,runtime.boottime -Filter @{"name" = "$VMHost"} | Select-Object Name, @{N="UptimeDays"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalDays),1)}}, @{N="UptimeHours"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalHours),1)}}, @{N="UptimeMinutes"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalMinutes),1)}}}
}
elseif ($Cluster) {
foreach ($VMHost in (Get-VMHost -Location $Cluster)) {Get-View -ViewType hostsystem -Property name,runtime.boottime -Filter @{"name" = "$VMHost"} | Select-Object Name, @{N="UptimeDays"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalDays),1)}}, @{N="UptimeHours"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalHours),1)}}, @{N="UptimeMinutes"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalMinutes),1)}}}
}
else {
Get-View -ViewType hostsystem -Property name,runtime.boottime | Select-Object Name, @{N="UptimeDays"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalDays),1)}}, @{N="UptimeHours"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalHours),1)}}, @{N="UptimeMinutes"; E={[math]::round((((Get-Date) - ($_.Runtime.BootTime)).TotalMinutes),1)}}
}
}
<#
.Synopsis
Shows the uptime of VMHosts
.Description
Calculates the uptime of VMHosts provided, or VMHosts in the cluster provided
.Parameter VMHosts
The VMHosts you want to get the uptime of. Can be a single host or multiple hosts provided by the pipeline
.Example
Get-VMHostUptime
Shows the uptime of all VMHosts in your vCenter
.Example
Get-VMHostUptime vmhost1
Shows the uptime of vmhost1
.Example
Get-VMHostUptime -cluster cluster1
Shows the uptime of all vmhosts in cluster1
.Example
Get-VMHost -location folder1 | Get-VMHostUptime
Shows the uptime of VMHosts in folder1
.Link
http://cloud.kemta.net
#>
}
You can use it in a couple of different ways, as documented in its help section (get-help get-vmhostuptime -expamples). But if you provide no input to it, it will generate an output like this:
Hopefully, you don’t have an uptime as long as some of these hosts 
