VMware PowerCLI 101 Blog Series

Consolidating my blogs on VMware PowerCLI.

VMware PowerCLI 101 - Part1 - Installing the module and working with stand-alone ESXi host
VMware PowerCLI 101 - Part2 - Working with vCenter server
VMware PowerCLI 101 - Part3 - Basic VM operations
VMware PowerCLI 101 - Part4 - Snapshots
VMware PowerCLI 101 - Part5 - Real time storage IOPS and latency
VMware PowerCLI 101 - part6 - vSphere networking
VMware PowerCLI 101 - part7 - Working with vROps
VMware PowerCLI 101 - part8 - Working with vSAN

Hope it was useful. Cheers!

Related posts

PowerShell quick start guide

vRealize Operations Manager 7.5 - Part7 - vSAN monitoring and troubleshooting

In this article, I will walk you through how to use vROps for vSAN monitoring and performance troubleshooting. It is always recommended to follow a systematic and established approach to troubleshoot problems. Before we start here is a link to one of my article which explains the scientific method of troubleshooting. 

Given below are some very useful content from VMware that talks about vSAN performance troubleshooting.

Performance Troubleshooting – Understanding the Different Levels of vSAN Performance Metrics
Performance Troubleshooting – Which vSAN Performance Metrics Should be Looked at First?
Troubleshooting vSAN performance

Performance is all relative and sometimes performance issues can be because of the wrong perception. So it is always good to validate it with actual numbers. Compare with a benchmark value or verify all relevant metrics before and after the issue has been reported. Now assume there is a storage issue in the environment. Given below is a systematic order to approach the problem, identify it correctly, isolate it and finally take necessary steps to resolve it. 

vSAN performance troubleshooting approach

1. Infrastructure: Perform vSAN cluster health check
2. Virtual machine level: Is there a storage issue observed at the application level?
3. Virtual machine level: Is there a storage issue per vmdk level?
1. Latency (vmdk)
2. IOPS (vmdk)
4. Cluster level: Look at operations overview at the cluster level
1. Latency
2. IOPS
5. Host level: Identify the IO type that has a performance issue
1. Read IO
2. Write IO
6. Host level: Collect/ analyze metrics of the storage objects
1. Storage adapter (vmhba)
2. Disk groups
3. Cache disk
4. Capacity disk 
7. Host level: Collect/ analyze metrics of the network objects
1. Physical adapter (vmnic)
2. vSAN network (vmk)

At this point, you have a clearly defined workflow in identifying and resolving the issue. So let's have a look at the various vROps dashboards that provides you end to end visibility of your stack and helps you easily identify and isolate the issue. If there is a problem or abnormality or unusual performance behavior in your vSAN environment, vROps will notify that with alerts based on various metric values it monitors using its inbuilt intelligence and analytics capabilities. Alert generation is based on symptom and alert definitions and this will finally affect the health, risk or efficiency badge of the respective object. Status of the badges, symptoms, alerts, recommendations, historical performance data and time stamps will be very useful in the process of troubleshooting and quickly finding the actual problem.

Infrastructure: Perform vSAN cluster health check

As a starting point, you can make use of integrated health checks from vCenter to verify your vSAN infrastructure.

To understand in-depth about vSAN health checks refer: https://vxplanet.com/2019/01/30/vsan-health-checks-explained-part-1/

Now to get a high-level overview, let's have a look into the health, risk and efficiency badges of vSAN cluster in vROps. Please refer to this blog article from VMware to get a detailed understanding of badges.

Health badge

Risk badge

Alerts

Virtual machine level: Is there a storage issue observed at the application level?

You can make use of application aware operations feature in vROps 7.5 to get full stack visibility. Given below are the list of applications that can be currently monitored using vROps 7.5.

Reference to application aware monitoring: https://blogs.vmware.com/management/2019/05/application-aware-operations-with-vrealize-operations-7-5.html

If your application is not supported or if application aware monitoring is not configured, then you can go with native application performance counters/ methods to identify whether the application itself is observing/ affected by storage latency, low IOPS, etc.

Virtual machine level: Is there a storage issue per vmdk level?

As a first step, you can use the "Troubleshoot a VM" dashboard to understand and track resource usage of a virtual machine.

Troubleshoot a VM - a

Troubleshoot a VM - b

Select the VM object to get more details. Below screenshot shows metrics related to a virtual disk.

Cluster level: Look at operations overview at the cluster level

vSAN operations overview dashboard

Troubleshooting vSAN dashboard

Troubleshooting vSAN - a

Troubleshooting vSAN - b

Troubleshooting vSAN - c

Host level: Identify the IO type that has a performance issue

Host level storage metrics

Host level: Collect/ analyze metrics of the storage objects

Metrics related to a disk group

Read cache and write buffer metrics of a disk group

Performance metrics of a capacity disk

Host level: Collect/ analyze metrics of the network objects

Metrics related to vmnic (physical NIC) and vSAN vmk

Metrics related to network objects will help to determine whether the performance issue is due to resource contention, network misconfiguration, hardware issue, etc.  

Hope it was useful. Cheers!

Related posts:

vRealize Operations Manager 7.5 - Part6 - Adding new symptoms and alert definitions

vRealize Operations Manager 7.5 - Part5 - Alerting

vRealize Operations Manager 7.5 - Part4 - High availability

vRealize Operations Manager 7.5 - Part3 - Rightsizing

vRealize Operations Manager 7.5 - Part2 - Configure vCenter adapter and dashboards overview

vRealize Operations Manager 7.5 - Part1 - Installation

References:

VMware PowerCLI 101 - Part4 - Snapshots

In this post, I will briefly explain how to make use of PowerCLI when working with virtual machine snapshots.

Take a snapshot of VM:
New-Snapshot -VM "New Virtual Machine" -Name snap1 -Description try1

Revert to a snapshot:
$snap = Get-Snapshot -VM "New Virtual Machine" -Name "snap1"
Set-VM -VM "New Virtual Machine" -Snapshot $snap -WhatIf
Set-VM -VM "New Virtual Machine" -Snapshot $snap 

Delete specific snapshot of a VM:
$snap = Get-Snapshot -VM "New Virtual Machine" -Name "snap1"
Remove-Snapshot -Snapshot $snap -WhatIf
Remove-Snapshot -Snapshot $snap 

Delete all snapshots of a VM:
Get-VM "New Virtual Machine" | Get-Snapshot | Remove-Snapshot -WhatIf
Get-VM "New Virtual Machine" | Get-Snapshot | Remove-Snapshot 

List all VMs with snapshots:
Get-VM | Get-Snapshot | Select-Object VM, Name, Description, SizeGB

List VMs with snapshots older than a week:
Get-VM | Get-Snapshot | Where {$PSItem.Created -lt (Get-Date).AddDays(-7)} | Select-Object VM, Name, Description, Created, SizeGB | Format-Table

Find the parent-child relationship of VM snapshots:
$vm = Get-VM "New Virtual Machine"
get-vm $vm | Get-Snapshot | Select VM,Name,Description,Parent,Children,SizeGB,IsCurrent,Created,Id | sort Created |  Format-Table

Hope it was useful. Cheers!

Related posts:

VMware PowerCLI 101 - Part3 - Basic VM operations

VMware PowerCLI 101 - Part2 - Working with vCenter server

VMware PowerCLI 101 - Part1 - Installing the module and working with stand-alone ESXi host

vRealize Operations Manager 7.5 - Part6 - Adding new symptoms and alert definitions

In my previous post, I tried to explain briefly about the alerting aspects in vROps and overall workflow of the alerting process. In this post, I will explain how to create custom symptom definitions and alert definitions based on a scenario. 

Scenario

User is running some latency-sensitive business-critical applications on the vSAN cluster. Below are the symptoms that he would like to define and alerts should be produced for the same and these should affect the "Efficiency" badge of the vSAN cluster object. 

1. Warning - when vSAN Cluster Read Latency is greater than 1 ms
2. Critical - when vSAN Cluster Read Latency is greater than 2 ms
3. Warning - when vSAN Cluster Write Latency is greater than 2 ms
4. Critical - when vSAN Cluster Write Latency is greater than 3 ms 

Sample screenshot of vSAN environment efficiency badge 

Step1: Add symptom definitions

Go to Alerts - Symptom Definitions - Click Add (+)

Select base object type: vSAN Cluster

Select the metric "Read Latency (ms) - double click on it twice so that you can define both warning and critical symptoms.

Provide symptom definition name, criticality and numeric value as required and click Save.

Now you can see the two symptoms which you have just created.

Similarly, create symptom definitions for vSAN Cluster Write Latency.

All 4 symptom definitions are created now.

Step2: Add alert definitions

Next step is to add alert definitions.

Go to Alerts - Alert Definitions - Click Add (+)

• Provide a name and description.

• Click on Base Object Type and select "vSAN Cluster"

• Click on Alert Impact and select Impact: Efficiency (this means this alert definition will affect the efficiency badge)

• Click Add Symptom Definitions (here you have to search for the symptom definitions that were created earlier and attach to this alert definition)

• Drag both symptom definitions to the right-hand side as shown in the screenshot (make sure to choose "Any" as highlighted below)

• Click Add Recommendations (here I added some sample recommendations) and click save

Similarly, create an alert definition for vSAN Cluster Write Latency alerts.

Now both alert definitions are created.

Let's verify current vSAN cluster Read/ Write latency in the dashboard.

As you can see above, Cluster I/O Write Latency is 2.67 ms which is greater than the warning threshold we defined. This means a warning alert should be produced and also should affect the efficiency badge of the vSAN Cluster object. An alert has already produced for this and can be seen in the second widget. It also shows the efficiency badge color is now yellow. If you click on the alert it will provide more details on the same.

If you browse the environment tab you can also notice that the efficiency badge of vSAN Cluster has turned to yellow.

Please feel free to share if this was useful. Cheers!

Related posts

vRealize Operations Manager 7.5 - Part5 - Alerting

vRealize Operations Manager 7.5 - Part4 - High availability

vRealize Operations Manager 7.5 - Part3 - Rightsizing

vRealize Operations Manager 7.5 - Part2 - Configure vCenter adapter and dashboards overview

vRealize Operations Manager 7.5 - Part1 - Installation

vRealize Operations Manager 7.5 - Part5 - Alerting

Alerting is a very important aspect of infrastructure monitoring. vROps has very powerful alerting capabilities. It might look a bit complicated for the first time. A good understanding of symptoms, alert definitions, badges, notification rules, etc. are required to effectively utilize the maximum functionality/ capabilities of vROps. In this post, I will try to explain all these alert settings. Before getting into the configurations, first, let's have a look at objects and object types in vROps.

Objects and object types

As you can see in the screenshot above there are many objects of type "Datastore". All these objects/ object types have "Metrics" and "Properties". Click on the "Show Detail" icon as shown below to view more details of the selected object.

Metrics and Properties

"Metrics" and "Properties" of the object "vol03" is shown below.

Symptom definitions and alert definitions

Based on the value of metrics/ property you can define symptoms with criticality Info, warning, critical, etc. Using symptom definitions alert definitions can be created and this generates corresponding alerts and will directly affect the badges associated with the object. Now let's have a look at some of the symptom definitions and alert definitions that are pre-defined in vROps for the "vCenter Adapter". Here I am taking an example of object type "Datastore".

Examples: Symptom definition

Select a symptom definition and click edit.

As you can see, this symptom definition produces a warning alert when any datastore "capacity used %" is greater than 90.

Another symptom definition is given below where an info alert will be generated when space remaining on the datastore is 0.

Example: Alert definition

As shown in the screenshot below there are few pre-defined alert definitions for object type "datastore". 

Let's select one alert definition.

Now, if you would like to forward these alerts to an email address or an SNMP trap destination, you will need to configure two things.

1. Outbound instance
2. Alert notification rules

Add outbound instance

I will be configuring an SNMP trap destination. Go to Administration - Management - Outbound settings - click on the + icon. Provide necessary details and test to ensure the connection is successful.

Add alert notification rule

By default, no notification rules are available in vROps. User has to create new rules as per the requirement. Go to Alerts - Alert settings - Notification settings - click on the + icon and provide necessary configuration details. As an example, I will configure alert notification rule to forward all datastore related alerts to an SNMP trap destination.

The above rule will forward all the alerts that impact health, risk, and efficiency badges of datastore object to the configured SNMP trap destination.

Summary of the alerting process in vROps

Hope it was useful. Cheers!

Related posts

vRealize Operations Manager 7.5 - Part6 - Adding new symptoms and alert definitions

vRealize Operations Manager 7.5 - Part4 - High availability

vRealize Operations Manager 7.5 - Part3 - Rightsizing

vRealize Operations Manager 7.5 - Part2 - Configure vCenter adapter and dashboards overview

vRealize Operations Manager 7.5 - Part1 - Installation