PowerCLI – Fetch Interesting stats or configuration for a list of VMs

Now and then I find that I need to retrieve some useful information from a variety of VMs, this usually involves me doing a Get-VM with some selections and criteria to search for. However sometimes the information I require about a VM is listed in the advanced configuration and not as easy to get to with a single cmdlet. I thought it would be really handy to have a PowerCLI function that would easily pull the useful information out for me and summarise it for any given VM or set of VMs.

 

With that said, I recently read a great blog post by Jonathan Medd (Basic VMware Cluster Compatibility Check), and after reading it I thought it would be a great idea to create a set of functions that provide me with the information I often use. To start, I thought I would do a function that lists the most useful or common information about VMs that I often search for. As well as speeding up the process of retrieving information about VMs, I thought it would also be good PS/PowerCLI practise for me to write more functions. The reason being that I often tend to do PowerCLI reporting scripts rather than actual functions that accept input from the pipeline or other parameters. Below is my function to collect some useful information about Virtual Machines – you can specify a VM with the -VM parameter or pipe a list of VMs to it, using Get-VM | Get-VMUsefulStats. Jonathan’s post also had an interesting section about the order in which output is displayed. You’ll need to pipe the output to Select-Object to change the order the information is fed back in, otherwise it will list the information in the default order. This is not really a problem anyway, just good to know if you are fussy about the order in which the output comes back in!)

 

So, here is the first function (Get-VMUsefulStats):

 

[download id=”7″]

 

function Get-VMUsefulStats {
<#
.SYNOPSIS
Fetches interesting or useful stats about VMware Virtual Machines

.DESCRIPTION
Fetches interesting or useful stats about VMware Virtual Machines

.PARAMETER VM
The Name of the Virtual Machine to fetch information about

.EXAMPLE
PS F:\> Get-VMUsefulStats -VM FS01

.EXAMPLE
PS F:\> Get-VM | Get-VMUsefulStats

.EXAMPLE
PS F:\> Get-VM | Get-VMUsefulStats | Where {$_.Name -match "FS"}

.LINK
http://www.shogan.co.uk

.NOTES
Created by: Sean Duffy
Date: 18/01/2012
#>

[CmdletBinding()]
param(
[Parameter(Position=0,Mandatory=$true,HelpMessage="Name of the VM to fetch stats about",
ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true)]
[System.String]
$VMName
)

process {

$VM = Get-VM $VMName

$VMHardwareVersion = $VM.Version
$VMGuestOS = $VM.OSName
$VMvCPUCount = $VM.NumCpu
$VMMemShare = ($VM.ExtensionData.Config.ExtraConfig | Where {$_.Key -eq "sched.mem.pshare.enable"}).Value
$VMMemoryMB = $VM.MemoryMB
$VMMemReservation = $VM.ExtensionData.ResourceConfig.MemoryAllocation.Reservation
$VMUsedSpace = [Math]::Round($VM.UsedSpaceGB,2)
$VMProvisionedSpace = [Math]::Round($VM.ProvisionedSpaceGB,2)
$VMPowerState = $VM.PowerState

New-Object -TypeName PSObject -Property @{
Name = $VMName
HW = $VMHardwareVersion
VMGuestOS = $VMGuestOS
vCPUCount = $VMvCPUCount
MemoryMB = $VMMemoryMB
MemoryReservation = $VMMemReservation
MemSharing = $VMMemShare
UsedSpaceGB = $VMUsedSpace
ProvisionedGB = $VMProvisionedSpace
PowerState = $VMPowerState
}
}
}

 

You can use the cmdlet to very easily retrieve information about a single VM or list of VMs. Examples:

 

Get-VMUsefulStats -VM NOOBS-VC01

Get-VM | Get-VMUsefulStats

 

To format the output in a neat table, pipe the above to Format-Table (ft) like so:

 

Get-VM | Get-VMUsefulStats | ft

 

The “MemShare” value is interesting – it is something I was specifically interested in, as some VMs I have worked with in the past have needed memory sharing to be specifically disabled, and this is something that needs to be changed with an advanced parameter on the VM. Therefore most (default) VMs will not have this entry at all and will appear blank in the output. (the parameter I am referring to for those interested is sched.mem.pshare.enable). Of course this most likely won’t be of any use to you, so feel free to omit this bit from the function, or feel free to customise the function to return information useful to your VMware deployment VMs. Here is an example of the output for one VM.

 

 

Anyway, I hope someone finds this useful, and please do let me know if you think of any improvements or better way of achieving a certain result.

 

VCP5 Exam review / experience

Today I passed my VCP 5 exam – a month before the cut off date for getting it done without the need to participate in the usual compulsory classroom training! (For those already holding the VCP 4 certification). It seems like just about everyone is doing one of these exam experience posts, so I thought I would join in and provide my feedback on the exam. I have also had a few people asking about how it went and for some advice on how best to study for the VCP 5 so hopefully this will be help to some. Parts of this post may be repeated information, but I will also detail my specific study routine below which will hopefully be helpful.

 

Whenever possible, I referred to the following two excellent VCP 5 study / advice pages – they are a great starting point and give a good overview of what you need to know and what you need to cover:

 

 

Next up, I got up to speed with the new VMware vSphere 5 features by doing the following:

 

  • Upgraded my home vSphere 4.1 lab environment to vSphere 5 – if you don’t already have a lab, I wrote a (fairly lengthy) article last year about creating one for yourself using VMware Workstation over at Simple-Talk – Read more here. There are various improvements that could be made to this lab environment article, such as using the newer Workstation 8.0, linked clones, and creating some of your VMs such as AD / vCenter within your nested ESXi VMs, so if you do take a look, keep this in mind and take a look else where for newer versions of Lab setups using vSphere 5.
  • TrainSignal VCP 5 DVD course – I got one of these ordered in and I watched the entire 17 hours set. Whilst some of it was repeated information for me – (working day in and day out with vSphere 4.x), there were still tons of new things I learnt and of course they cover all of the new vSphere 5 features in some fairly decent detail which was what I was primarily after! It was also good to get a refresher on vDS networking as I don’t use that too often in my day to day duties. Elias and David do a great job of explaining each feature and going through hands on installations / configurations.
  • Lab work – I tried out all of the new features (except Auto Deploy) in my upgraded vSphere 5 lab environment at home. I still need to set up Auto Deploy to try it out for myself, but the TrainSignal DVD covered that for me, and I also read up about it in the official VMware documentation.
  • Duncan Epping & Frank Denneman’s VMware vSphere 5 Clustering Technical Deepdive book – I grabbed a copy on Kindle – this is a great resource to read up about the clustering features, and after reading through their “4.1 edition” whilst I was on holiday last year, I knew I was definitely going to be grabbing this latest refresh. I didn’t have time to read this through before my exam, but I did do a quick refresher on the new HA in vSphere 5 before the exam – it was very useful to know more about the inner workings of FDM and find out more about the new Master / Slave functionality of HA.

 

The important stuff that you need to know:

 

  • VCP 5 Blueprint – currently, the latest version of this document is 1.41 – I used this and made sure I was up to speed on every section by downloading and reading VMware documentation on each objective in the blueprint. I also read a few blogs who covered the objectives in the blueprint with summarised notes and these were helpful to recap with.

 

Practise questions / tests

 

  • Simon Long’s SLOG has some great practise questions to try out – I used these a couple of times to practise with – you won’t get these questions in the exam of course, but they are good to check that you know your stuff and practise with.
  • VMware Practise exam – this is the official VMware practise exam – I took it once I was happy I was pretty much up to speed with everything. The practise exam I took on the VMware site had 30 questions to do in around 45 minutes. Apparently if you get a full 100% you can’t take it again, so they recommend you purposely answer one question incorrectly to ensure you don’t throw away your chances of using it again. I did this the day before my exam to see how I was doing.

 

Final thoughts

 

Finally, I would agree with most other bloggers out there – the VCP 5 is a bit more challenging than the VCP 4 exam. I didn’t come across any configuration maximum questions myself, so this is good news, as I honestly thought they were a bit of a waste of time in the VCP 4 exam – they are simple facts that can easily be looked up in documentation – useful in some cases, but not in practise. The VCP 5 exam seemed to cover a good deal of troubleshooting scenarios which is what counts in my opinion, and seems more relevant! All in all, it was a challenging, yet satisfying exam!

 

How to see if a Device/Datastore supports VAAI on ESXi 5 using ESXTOP or ESXCLI

Previously, using my home lab environment I had wondered how to check to see if my shared storage was using VAAI (VMware Storage APIs for Array Integration) – this is a technology that provides hardware acceleration functionality for your storage in vSphere, and was first introduced for vSphere ESX(i) 4.1. Essentially, this allows your hosts to offload certain virtual machine and storage management functions to hardware that supports VAAI.

 

The very first way I found I was able to see if VAAI was active on a datastore was by using ESXTOP. Silly – as it is quite a long-winded way of determining this, but it gave me an idea of whether it was in use or not. Anyway, to get to this ESXTOP view, go to your devices screen (press u) and remove a few columns that are taking up room (press F to add/remove columns), toggle all columns except the DEVICE name column, then add the counters we are interested in for VAAI. (press O – for VAAISTATS). Like so:

 

 

Now you can see the VAAI statistics for your datastores/devices in ESXTOP – notice how my HP/LHN P4000 VSA lab iSCSI datastores are showing VAAI stats as expected, whereas my shared NFS Datastores from a FreeNAS appliance are blanked out / not supported in the screenshot below:

 

 

 

Here is a useful list of ESXTOP counters that are explained in detail if you are wondering what each of these shows exactly: http://communities.vmware.com/docs/DOC-11812 – Section 4.2.9 shows ZERO statistics specifically, which is one of the features VAAI can help hosts offload to hardware.

 

So now, for a slightly easier / clearer way of viewing whether VAAI is active or not – we can use esxcli!

 

Connect up to an ESXi 5 host using SSH or the DCUI and issue the following command (Where the device identifier is specified after -d) – remember to find the device identifier applicable to the device you want to check for VAAI status on – one way of doing this is to identify the datastore using your vSphere client – Hosts & Clusters view -> Select ESXi host -> Configuration -> Storage -> Devices View tab -> Look for device identifier in the name column. Once you have your device ID, issue the command below:

 

esxcli storage core device list -d naa.6000eb3afd81276200000000000000bd

 

You will get a list out of the device along with various settings and feature statuses. We are specifically looking for “VAAI Status” – if it is enabled, we will see “VAAI Status: enabled” as in the example below.

 

 

Brian Ragazzi has also showed an even easier method (thanks Brian!) to get a list of devices along with their VAAI feature support listed using:

 

esxcli storage core device vaai status get

 

using “esxcli storage core device vaai status get” to get VAAI status for devices

 

Interestingly, whilst researching this, I came across a blog post by Jason Langer who also explains the first method I showed above of checking VAAI status – in his case he was using Netapp storage and found some other interesting caveats along the way in terms of getting VAAI enabled on his hosts with his particular device. Well, I hope this post helps and as always, if you spot anything out of place – feel free to chime in on the comments section!

 

Get vCenter User Sessions and Idle times with PowerCLI

Today I was looking into a small “nice to have” notification system for users that had left their vSphere clients open and logged into vCenter. I found this great bit of script to list currently logged in users over at blog.vmpros.nl and thought I would expand on this in my own way to generate a handy list of logged in users and their current idle time – similar to the way the “Sessions” tab in the vSphere client displays user session information. When I got home this evening I expanded on the original script from vmpros.nl to create the following:

 

$Now = Get-Date
$Report = @()
$svcRef = new-object VMware.Vim.ManagedObjectReference
$svcRef.Type = "ServiceInstance"
$svcRef.Value = "ServiceInstance"
$serviceInstance = get-view $svcRef
$sessMgr = get-view $serviceInstance.Content.sessionManager
foreach ($sess in $sessMgr.SessionList){
   $time = $Now - $sess.LastActiveTime
   # Our time calculation returns a TimeSpan object instead of DateTime, therefore formatting needs to be done as follows:
   $SessionIdleTime = '{0:00}:{1:00}:{2:00}' -f $time.Hours, $time.Minutes, $time.Seconds
   $row = New-Object -Type PSObject -Property @{
   		Name = $sess.UserName
		LoginTime = $sess.LoginTime
		IdleTime = $SessionIdleTime
	} ## end New-Object
	$Report += $row
}
$Report

 

[download id=”6″]

 

Here is an example of the output of the script:

 

Using this bit of PowerCLI script, it should be easy for you to create your own notification system based on user session idle time, or some functionality that would disconnect idle users. Let me know if you do improve on the above, or if you have any other suggestions.