How to retrieve ESX and local datastores with Powershell

I have been asked to individuate all the ESX that need being remediated as well as retrieve the capacity of their local storage to see if some of them might need larger disks to be bought.

There are a few hundreds ESX in that server farm, so I am going to show you how I used Powershell and PowerCLI cmdlets to retrieve exactly what I wanted.

The aim of my script is to return a custom Powershell object (aka PSObject) that contains all the needed properties for later analysis.

These properties are: the ESX name, model, version, build and all of its local datastores with their capacity. This last one in particular I retrieve it using the MultipleHostAccess property.

Here's the script I wrote:

1. function Get-Esxinfo {  
2. <#  
3.   .SYNOPSIS  
4.     This script returns information on one or more ESX.  
5.    
6.   .DESCRIPTION  
7.     This script returns information on one or more ESX.  
8.     You can run the script against one or more ESX.  
9.     This script can display the information in a spreadsheet.  
10.    
11.   .PARAMETER Server  
12.     Specify the vSphere servers on which you want to run this function.  
13.    
14.   .PARAMETER Name  
15.     Specify the names of the hosts you want to retrieve.  
16.     By default this script will retrieve all the ESX hosts connected to the current vCenter.  
17.    
18.   .PARAMETER Filepath  
19.     Specifies the path to the CSV output file. The default is 'esxinfo.csv'. This file will be saved in the local temp folder.  
20.       
21.   .PARAMETER OpenFile  
22.         Opens the output file with the program associated with CSV files.  
23.            
24.   .PARAMETER PassThru  
25.         Returns the object.  
26.    
27.   .EXAMPLE  
28.         Get-Esxinfo -server virtualcenter  
29.         Gets information for all the ESX connected to VIserver named 'virtualcenter'.  
30.           
31.   .EXAMPLE  
32.         Get-Esxinfo -server virtualcenter -name esx00*  
33.         Gets information for all the ESX whose name starts with esx00* connected to VIserver named 'virtualcenter'.  
34.   
35.   .EXAMPLE  
36.         $EsxServers = Get-Content ESXServers.txt  
37.         $EsxServers | Get-Esxinfo -server virtualcenter -openfile -passthru  
38.         Gets the information from all the ESX listed in ESXServers.txt  
39.         Opens the output file with the program associated with CSV files.  
40.         Returns the object.  
41.   
42.   .EXAMPLE  
43.         Get-Esxinfo -server virtualcenter -verbose | format-table  
44.         Gets information for all the ESX connected to VIserver named 'virtualcenter' and show the output in a table.  
45.         Show verbose information.  
46.   
47.    .INPUTS  
48.     System.String  
49.     
50.   .OUTPUTS  
51.     PSObject  
52.            
53.   .NOTES  
54.     Author: happysysadm.com  
55.     Created: 27Avril2013  
56.   
57. #>  
58.   
59. #requires -version 2.0  
60.   
61. [CmdletBinding()]  
62.   
63. param(  
64.     [Parameter(Mandatory=$true)]  
65.     [string[]]$server,  
66.       
67.     [Parameter(Mandatory=$false,ValueFromPipeline=$True,ValueFromPipeLineByPropertyName=$True)]  
68.     [string[]]$name="*",  
69.       
70.     [Parameter()]  
71.     [ValidateScript({  
72.         if((Test-Path -LiteralPath $_ -IsValid) -and ($_ -like '*.CSV'))  
73.             {  
74.             $true  
75.             }  
76.         else  
77.             {  
78.             throw ('The specified path "{0}" is invalid. Valid arguments include a path to a CSV file. Exiting.' -f $_)  
79.         }  
80.     })]  
81.     [string]$filepath = (Join-Path -Path ([System.IO.Path]::GetTempPath()) -ChildPath "esxinfo.csv"),  
82.   
83.     [Parameter()]  
84.     [switch]$OpenFile,  
85.            
86.     [Parameter()]  
87.     [switch]$PassThru  
88. )  
89.   
90. write-verbose "Adding VMware Powershell Snapin"  
91. IF (-not (Get-PSSnapin VMware.VimAutomation.Core -ErrorAction SilentlyContinue)) {  
92. Add-PSSnapin VMware.VimAutomation.Core  
93. }  
94.   
95. write-verbose "Connecting to vCenter"  
96. try  
97.     {  
98.     Connect-VIServer $server  
99.     }  
100. catch  
101.     {  
102.     Write-Warning "An error occured.`n$_`nExiting..."  
103.     break  
104.     }  
105.   
106. write-verbose "Preparing the wrapper for the returned psobjects"  
107. $esxarray = @()  
108.   
109. write-verbose  "Retrieving the ESX information and storing it in an array (can take a bit...)"  
110. try  
111.     {  
112.     $esxsource = @(Get-VMHost -Name $name)  
113.     }  
114. catch  
115.     {  
116.     Write-Warning "An error occured.`n$_`nExiting..."  
117.     break  
118.     }  
119.   
120. write-verbose "Counting the number of ESX to show a progress bar"  
121. $totalesx = ($esxsource).count  
122.   
123. write-verbose "Initialiasing a counter"  
124. $a = 0  
125.   
126. foreach($esx in $esxsource)  
127.     {  
128.     write-verbose  "Creating a psobject and adding members to it"  
129.     $esxobject = New-Object -typename psobject   
130.     $esxobject | add-member -membertype noteproperty -name 'ESX Name' -Value $esx.name  
131.     $esxobject | add-member -membertype noteproperty -name 'ESX Model' -value $esx.model  
132.     $esxobject | add-member -membertype noteproperty -name 'ESX Version' -value $esx.version  
133.     $esxobject | add-member -membertype noteproperty -name 'ESX Build' -value $esx.build  
134.       
135.     write-verbose  "Retrieving local datastores only, LUNs are excluded because they are not local hardware"  
136.     $datastores = Get-Datastore -VMHost $esx | Get-View | ?{$_.Summary.MultipleHostAccess -match 'false'}  
137.     $i = 1  
138.     foreach($datastore in $datastores)  
139.         {  
140.         $esxobject | add-member -membertype noteproperty -name "ESX $i datastore name" -value $datastore.summary.name  
141.         $esxobject | add-member -membertype noteproperty -Name "ESX $i datastore capacity GB" -value ($datastore.summary.capacity /1GB)  
142.         $i++  
143.         }  
144.     write-verbose "Adding PSObject to array"  
145.     $esxarray += $esxobject  
146.       
147.     write-verbose "Removing psobject to be reused"  
148.     $esxobject = $null  
149.     $a++  
150.       
151.     write-verbose "Writing a progress bar"  
152.     Write-Progress -Id 1 -Activity ("Querying ESX") -PercentComplete ($a / $totalesx * 100) -Status ("Queried {0} ESX of {1}" -f $a, $totalesx)  
153.     }  
154.   
155. write-verbose "Going to write array content to $filepath"  
156. try  
157.     {  
158.     $esxarray | Export-Csv -UseCulture -NoTypeInformation $filepath  
159.     }  
160. catch [System.IO.IOException]  
161.     {  
162.     Write-Warning "Unable to write to $filepath. File could be in use.`n$_`nExiting..."  
163.     break  
164.     }  
165. catch  
166.     {  
167.     Write-Warning "An error occured.`n$_`nExiting..."  
168.     }  
169.       
170. write-verbose "Opening file if asked so"  
171. if ($OpenFile)  
172.         {  
173.         Invoke-Item -Path $FilePath  
174.         }  
175.   
176. write-verbose "Returning psobject if asked so"  
177. if ($PassThru)  
178.     {  
179.     $esxarray  
180.     }  
181.               
182. }  
183.   
184. Get-Esxinfo -server virtualcenter -name myesx* -verbose -PassThru -OpenFile | ft  

The only mandatory parameter is the name of your vCenter, which is used for initial connection. Other optional parameters are the name of the ESX to retrieve (* is used in case you specify none), the name of the logfile (which will be saved in your temp folder), and the possibility to invoke the program associated with CSV files (-openfile).

As you can see I create two hashtables:

• one for containing the output of the get-vmhost command, so that later queries can quickly be done against this object instead of waiting for powershell to query the vCenter database again and again;
• one for containing every ESX object with its properties.

Interesting articles that explain the use of PSObject and that I suggest you to read are:

• New-Object PSObject –Property [HashTable]
• Create a Truly Advanced PowerShell Function
• Windows PowerShell: The Many Ways to a Custom Object

I would also like to point out the use I made of a progress bar. This is a nice Powershell feature which is often overlooked by scripters. I like the idea of having this pop-up bar, so I deeply suggest getting used to it because its syntax is not so diffcult.

Note that the appearance of the progress bar varies when it is used at the Powershell prompt or within the PowerGUI:

Powershell write-progress as it appears at the prompt

Powershell write-progress as it appears in PowerGUI

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