Friday, October 18, 2019

Docker 101 - Part2 - Basic operations

In this article, I will walk you through basic Docker commands and how to work with it for creating, managing, and monitoring Docker containers.

Docker version and info


#docker version


#docker info


Default directory for Docker


#cd /var/lib/docker


Pull images


#docker pull centos:latest 


List images


#docker images


Create bridge network


#docker network create -d bridge --subnet 10.0.0.0/24 ps-bridge

List all bridge networks


#brctl show

Inspect a network 


#docker network ls
#docker network inspect <name>




Run a container


#docker run -dt --name centos_test --network ps-bridge centos sleep 900


SSH into a container


#docker exec -it <name> sh


List running containers


#docker ps


List all containers


#docker ps -a

List container stats


#docker stats


Stop a container


#docker stop <Container ID>


Remove a container


#docker rm <Container ID>

Remove an image


#docker rmi <REPOSITORY:TAG>



Hope it was useful. Cheers!

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References



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Docker 101 - Part1 - Installation

Enter cloud native! In this article, I will briefly explain how to build a virtual Docker host. Here I am installing Docker on a CentOS 7.4 virtual machine running on ESXi 6.5 which is part of a VMware vSAN cluster.

Prerequisites:
  • Deploy a basic CentOS 7.4 VM
  • Assign IP address and ensure the VM has internet connectivity
  • You should have root creds

Installation:
  • SSH to the CentOS VM as root
  • yum check-update
  • yum install -y yum-utils device-mapper-persistent-data lvm2
  • yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
  • yum install docker-ce
  • systemctl start docker
  • systemctl enable docker
  • systemctl status docker

Verify version:
  • docker version

Run your first container:
  • docker run hello-world

Hope it was useful. Cheers! In the next part, I will explain basic Docker commands and operations.

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Wednesday, October 9, 2019

vRealize Operations Manager 7.5 - Part8 - Super Metrics

In this article, I will briefly explain about using super metrics in vROps 7.5. For example, I will take the VM NUMA optimization super metric which was released recently. You can download the super metric JSON file from the VMware sample exchange. 

Once the JSON file is downloaded, login to your vROps instance. Navigate to Administration - Configuration and select Super Metrics. Click on Import Super Metric.


Browse and select the JSON super metric file that you downloaded. Click DONE.


Once it is done, you can see the two super metrics. 


To enable the super metric in a policy:
Select the super metric - Edit Selected Super Metric - Goto Enable in a Policy  - Select vSphere Solution's Default Policy and click FINISH.


Now after the default collection interval, you can see the super metric tab as shown below. 


As you can see in the above screenshot, for this virtual machine "lustre01", recommendations are: 
  • NUMA optimal CPU socket: 1 
  • NUMA optimal CPU cores per socket: 8

Hope it was useful. Cheers!

References


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Monday, October 7, 2019

VMware PowerCLI 101 - Part5 - Real time storage IOPS and latency

It is very important to monitor and analyze the performance of storage subsystem components as it direcly affects the application performance. In this article, I will briefly explain how to use PowerCLI to get real time storage IOPS and latency of the following: 

              • Virtual disk
              • Datastore
              • Disk/ LUN 
              • Storage adapter
              • Storage path
Connect to vCenter server using:
Connect-VIServer <IP address of vCenter>

To understand the list of all available stats for a specific entity, you can use Get-StatType. For example, to list all real time stats for a virtual machine you can use:
Get-StatType -Entity <VM name> -Realtime | sort

Virtual disk

To get real-time IOPS and latency of all virtual disks of a VM named 'lustre01':
Get-Stat -Entity lustre01 -Realtime -MaxSamples 1 -Stat virtualDisk.numberReadAveraged.average,virtualDisk.numberWriteAveraged.average,virtualDisk.totalReadLatency.average,virtualDisk.totalWriteLatency.average | sort Instance,MetricId | select MetricId, Value, Unit, Instance




Datastore

To get real-time IOPS and latency of a datastore (with Uuid: 5bea72bb-5d72ed6a-1d85-246e96792988) from an ESXi host (IP: 192.168.105.10):
Get-Stat -Entity 192.168.105.10 -Stat datastore.numberReadAveraged.average,datastore.numberWriteAveraged.average,datastore.totalReadLatency.average,datastore.totalWriteLatency.average -Realtime -MaxSamples 1 -Instance 5bea72bb-5d72ed6a-1d85-246e96792988 | Select MetricId, Value, Unit, Instance | Sort-Object MetricId

Note: You can get Uuid of a datastore using (Get-Datastore vol01).ExtensionData.Info.Vmfs.Uuid


Refer my article "Real time VMware datastore performance monitoring using PowerShell" for monitoring the real time performance statistics of multiple shared VMFS datastores which are part of a multi-node VMware ESXi cluster.

Disk/ LUN

To get real-time IOPS and latency of a disk (eui.387de1af35b93f6ff0a9bef000000000): 
Get-Stat -Entity 192.168.105.10 -Disk -Realtime -Instance eui.387de1af35b93f6ff0a9bef000000000 -MaxSamples 1 -Stat disk.numberWriteAveraged.average,disk.numberReadAveraged.average,disk.totalWriteLatency.average,disk.totalReadLatency.average | Select MetricId, Value, Unit, Instance


Storage adapter

To get real-time IOPS and latency of a storage adapter: 
Get-Stat -Entity 192.168.105.10 -Realtime -MaxSamples 1 -Stat storageAdapter.totalReadLatency.average, storageAdapter.totalWriteLatency.average, storageAdapter.numberReadAveraged.average, storageAdapter.numberWriteAveraged.average -Instance vmhba64 | Select-Object MetricId, Value, Unit, Instance | Sort-Object MetricId


Storage Path

To get real-time IOPS and latency of a storage path:
Get-Stat -Entity 192.168.105.10 -Realtime -MaxSamples 1 -Stat storagePath.totalReadLatency.average, storagePath.totalWriteLatency.average, storagePath.numberReadAveraged.average, storagePath.numberWriteAveraged.average -Instance fc.300fb123ba76519c:b436362bae5b217-fc.300fb123ba76519c:b436362bae5b217-eui.387de1af35b93f6ff0a9beec00000001 | Select MetricId,Value,Unit,Instance | Sort-Object MetricId


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Thursday, September 19, 2019

vRealize Operations Manager 7.5 Blog Series

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Wednesday, September 18, 2019

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.  


References:





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Wednesday, August 7, 2019

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!

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