Capacity planning using vRealize Operations Manager Version 6.x.

Difference between Demand based Model and Allocation Based Model

In this article I share few points which might help one get more understanding on these capacity planning models.

The Demand Model element:

If you adopt a demand based policy, the capacity planning engine will only consider the   resources that are actually being used, or demanded, as consumed. So, if your 4x vCPU, 8 GB RAM, 40 GB disk VM is only using 2 vCPU, 5 GB RAM, and 20 GB disk space, the remaining resources are reported as having Some capacity still available.

The Allocation Model element:

Determines how vRealize Operations Manager calculates capacity when you allocate a specific amount of CPU, Memory and storage resource to clusters.

As allocation calculations here can be done with certain ratio or percentage of actual physical resources.

For CPU its vCPU to pCPU ratio
For Memory it is over commitment
For Storage it is thin provisioning

Questions like which policy is Ideal for Me? What is the ideal vCPU/pCPU ratio if I am using allocation based model? Is memory over commitment recommended for production environment? etc are all design based and the answers differ from environment to environment.

Customer has to work out a vCPU/pCPU ratio that fits his environment. The ideal approach would be to start with a big ratio like 8:1 and then monitor the stats. If stress comes into picture then the ratio can be decreased to something like 5:1 and so on.

Example showing difference in capacity remaining with Allocation and demand models


Below are 4 default vRealize Management policies available for customers to do capacity planning although a custom policy can be created by customer starting from scratch.

VMware Production Policy (Demand only)
Optimized for production loads, without using allocation limits, to obtain the most capacity.

VMware Production Policy (with Allocation)
Optimized for production loads that require the demand and allocation capacity models.
No over commitment for Mem and storage. Over commitment available in CPU.

VMware Production Policy (without Allocation)
Optimized for production loads that require demand capacity models, and provides the highest overcommit without contention.
Over commitment available in CPU, Mem and Storage

VMware Test and Dev Policy (without Allocation)
Optimized for Dev and Test environments to maximize capacity without causing significant contention, because it does not include capacity planning at the virtual machine level.
The key deference in these policies comes to whether we allow over commitment or not.
And if we allow over commitment then is it allowed for CPU, Memory or Storage or for all.

A breakdown of each policy capacity analysis can be seen to decide which metrics we need to include to further tweak the policy to our needs. The accuracy and value of capacity management views and reports relies on an administrator’s ability to correctly translate their environmental requirements into policies.

To navigate to these policies and to check/edit the matrices covered.





Spend time and dig deep… this could be a onetime investment with lot of returns for vSphere Admin..

Setup vRealize Log Insight- Deployment & Integration

This article is about setting up vRealize Log Insight and integrating it with vSphere and vRealize Operations Manager.
Log Insight provides powerful real-time log management for VMware Environment with machine learning based intelligent grouping and faster search. This allows for swift troubleshooting and better analytics across physical and Virtual Environments.

It’s only a matter of exploring the options the tool gives for log analysis and you will enjoy using it.

The deployment can be broken down into below steps.

  • Pre-requisites
  • Deploy the Appliance
  • Configuration
  • Integration with vSphere and vROPS


Log Insight accepts data from sources(Virtual/Physical/Cloud) which use syslog protocol, sources that write logs and can run the vRealize log insight Agent and sources that can post data with HTTP/HTTPS through the REST API.

Ports for syslog feeds: 514(UDP), 514(TCP), 1514(TCP) SSL.


The appliance can be deployed in 4 configurations based on the sizing requirements. The configuration decide the amount of compute and storage resources the appliance requires.


The below link for sizing calculator will help you determine sizing

Deploying the Appliance

Login to the vSphere Web Client once the .OVA is available

Deploy OVF Template from vCenter and select Local file.

Browse and Select the .ova file

Click Next

Name the appliance and select location

Click Next

Select Resource and Review Details


Click Next


Accept the EULA and click Next


Choose the Configuration and Click Next


Select Storage and click Next


Select Network and click Next



Provide Network and Other Properties


Review and Click Finish.


The initial configuration is available after the appliance deployment


Welcome screen Click Next


Click Start New Deployment unless you are deploying this as a second node to an existing Log Insight to make a cluster(HA)


Provide email ID and admin password


Provide License Key.



Admin email for Notifications


SMTP configurations




Integration with vSphere and vRealize Operations Manager

Login to https://vRealizeLogInsight.hostname

Go to Administration.

Click vSphere under Integration


Provide vCenter FQDN and Credentials.


It is recommended to create a Custom User for Integration with below privileges on vCenter root.

  • Configuration.Change settings
  • Configuration.Network configuration
  • Configuration.Advanced settings
  • Configuration.Security profile and firewall

Once configured you will notice the Syslog setting and firewall configuration done on the ESXi hosts.


Go back to the Administration page and click vRealize Operations under Integration.


This allows you to access the Log Insight dashboard from the vRealize Operations Manager page.


I would also suggest you to go through the below link for a quick go through on Searching and Filtering event. You will need this coz there will lot of events if it’s a big infrastructure and you’ll have to find what you are looking for.

vRealize Operations Manager Custom Views and Reports


I have been using vRealize Operations Manager for quite some time now. There is huge amount of data available to the admin in the form of views, reports, heat maps etc. to have a very clear picture of the vSphere Environment.
As much as I like the solution, I felt the need for some custom views/reports for my own ease.
Also, it’s nice to make use of such options and utilize Enterprise license features.

I recently created a custom view and report to monitor snapshot usage and age.

I will continue to create custom view/reports and update this page accordingly.

Custom Report for Snapshot size of the VMs

Every report is based on a view. If you want to create a custom report you can either use one or more of the many existing views in vROPs or create a custom view for yourself.

A View can be defined as a container that takes Data from a Subject and Presents it in a format desired by the admin.

In the below view created for snapshot usage the above terms are explained.

Subject is the entity for which the data is required. It can be a VM, ESXi host, Datastore or any other vSphere inventory object.

Data is the Metrics and Properties of the object that you are expecting. It can be IO, Memory Usage, VMtools status, Packet drop or any statistics of an object that can be measured.

Custom View

As an example if you select VM as a subject you have 2 types of data available

  • Metrics: If you select this you can list resource usage like CPU, Memory, disk space etc.
  • Properties: If you select this you can list Properties of the VM like Memory reservation, VMtools status, Policy, custom tag etc.

In the view for snapshot usage select the subject as Virtual Machine

In Data, Select Metrics and Select Snapshot Space (GB) under Disk Space. Add a filter for Snapshot Space greater than Zero to list only VMs which has snapshots. Else the view would list all the VMs with snapshot size as 0 GB.
To include snapshot age, swap to properties under Data and select Snapshot Age.

Snapshot Size

Snapshot Age

This view now lists all the VMs which have snapshot size greater than Zero and mention snapshot age.

We can use this view to create a Custom report which can be emailed to the admin using a schedule.

vRealize Operations Manager upgrade

I recently upgraded vRealize Operations Manager from 6.0.1 to 6.6.1. Although the steps are pretty simple, I thought I would share them.

The upgrade was done in 2 Batches which is the required procedure as per the linked VMware KB below.

Stage 1: Upgrade form 6.0.1 to 6.3.1
Stage 2: Upgrade from 6.3.1 to 6.6.1

As I am using the vROPs Appliance I downloaded below files.



It is recommended to take a VM snapshot with memory and avoid Quiesing before you begin.

Take the cluster offline and proceed with upgrade, as long as the cluster is offline there will be no data collection. You might want to export any Custom policies, alerts etc. before you upgrade so that you can import them back after the upgrade has been successful.

Each Stage has 2 parts.

  • Operating System Upgrade
  • Upgrade Virtual Appliance

The 1st file to be uploaded is the OS.pak file, if the file upload reports that the file has already been installed you can check the option install the PAK file even if it is already installed.

It is very critical that we apply the OS upgrade first and then the appliance upgrade.
In case the Appliance upgrade is done 1st you will have to revert the snapshot or follow the below KB.

The upgrade is performed from software update from the admin console.






The appliance reboots multiple times throughout the whole upgrade process.



After upgrade is successful, login to the user interface and explore the new dashboards and other features.

Among multiple new features and the new look and feel of the product, you will realize that the plugin from vSphere Web client which redirected to the vRealize operations for a vSphere object has disappeared.

It’s something which has been removed in vRealize Operations Manager 6.6

Check the release notes below:

vCenter Mob after upgrade(reporting old version)


Follow the article to remove the plugin from vCenter MOB 

Hopefully VMware will put the feature back, as it was quite handy…

Replace vRealize Operations Manager SSL certificates.

This article shares the steps performed to replace/configure custom (CA signed) SSL certificate for vRealize Operations Manager. The replaced certificates are only for the web UI component of the solution and will be used to secure the communication with clients over the user interface.

I have vRealize 6.6.1 build 6163035 in my lab.

Below are the requirements for setting up custom SSL certificates for vRealize Operations manager.

The requirements along with the certificate replacement link can be found in the vRealize Operations Manager admin console.



There are 2 steps in the procedure

  1. Getting the SSL certs created from openSSL and CA.
  2. Installing the generated pem file.

OpenSSL version Win32OpenSSL_Light-1_1_0g used.

  • Create a folder to place all your Certificate related files.


  • Create the config file as below(Change the req_distinguished_name and  v3_req as per your appliance.

Openssl.cfg file:


 [ req ]
default_bits = 2048
default_keyfile = rui.key
distinguished_name = req_distinguished_name
encrypt_key = no
prompt = no
string_mask = nombstr
req_extensions = v3_req
[ v3_req ]
basicConstraints = CA:FALSE
keyUsage = digitalSignature, keyEncipherment, dataEncipherment
extendedKeyUsage = serverAuth, clientAuth
subjectAltName = DNS:vsom.mylab.local, DNS:, DNS:vsom
[ req_distinguished_name ]
countryName = AE
stateOrProvinceName = DXB
localityName = DUBAI
0.organizationName = mylab.local
organizationalUnitName = IT
commonName =vsom.mylab.local
  • openssl req -new -nodes -out  C:\Users\hussain\Desktop\vsom\vsom.csr -keyout C:\Users\hussain\Desktop\vsom\vsom-orig.key -config C:\Users\hussain\Desktop\vsom\openssl.cfg
  • openssl rsa -in C:\Users\hussain\Desktop\vsom\vsom-orig.key -out C:\Users\hussain\Desktop\vsom\vsom.key
  • Submit the generated csr to the CA and download the certificate in Base-64 format.
  • Download the root certificate of the CA.
  • Generate the .pem file containing the .cer, the root certificate and private key.
    type C:\Users\hussain\Desktop\vsom\vsom.cer C:\Users\hussain\Desktop\vsom\vsom.key C:\Users\hussain\Desktop\vsom\root.cer > vsom.pem
  • The generated .pem file looks something like this


2) Install the generated pem file using the admin UI.


Although the process is pretty straightforward I encountered an error due to incorrect time configuration of the vROPS appliance. once the date and time of the appliance were correctly set, the certificate could be replaced.

error: Certificate is not yet valid


helpful links: 



VMFS locking and ATS Miscompare issues

Brief about VAAI

By now, almost all the VMware techies are aware of what VAAI is, however I will add a little brief for those who are not.

VMware vSphere Storage APIs – Array Integration (VAAI), also referred to as hardware acceleration or hardware offload APIs, are a set of APIs to enable communication between VMware vSphere ESXi hosts and storage devices. The APIs define a set of “storage primitives” that enable the ESXi host to offload certain storage tasks like cloning, zeroing to the storage array and improve performance.

The goal of VAAI is to help storage vendors provide hardware assistance to speed up VMware I/O operations that are more efficiently accomplished in the storage hardware.

Most of the new arrays (FC/iSCSI/NAS) which support vSphere 5 and later usually support VAAI also (vSphere APIs for Array integration).However this can be verified from VMware HCL.

Listing the fundamental operations are controlled by these advanced settings:

Advanced Parameter name Description
HardwareAcceleratedLocking Atomic Test & Set (ATS), which is used during creation of files on the VMFS volume
HardwareAcceleratedMove Clone Blocks/Full Copy/XCOPY, which is used to copy data
HardwareAcceleratedInit Zero Blocks/Write Same, which is used to zero-out disk regions


This is a list of commonly used SCSI opcodes related to VAAI operations:

0x93 WRITE SAME(16)
0x41 WRITE SAME(10)
0x42 UNMAP


NOTE: Check the below link for more info on VAAI

In a shared storage environment, when multiple hosts access the same cluster filesystem (VMFS datastore), specific locking mechanisms are used. These locking mechanism prevent multiple hosts from concurrently writing to the metadata and ensure no data corruption.

VMFS supports SCSI Reservations and Atomic Test and Set (ATS) locking.


ATS is a lock mechanism designed to replace SCSI reservations. With the amount of SCSI reservation conflict issues on older versions of ESX/ESXi this was a much needed feature.

ATS modifies only a disk sector on the VMFS volume whereas a SCSI reservation locks the whole LUN. When successful, it enables an ESXi host to perform a metadata update on the volume. This includes allocating space to a VMDK during provisioning, because certain characteristics must be updated in the metadata to reflect the new size of the file. The introduction of ATS addresses the contention issues with SCSI reservations and enables VMFS volumes to scale to much larger sizes. ATS has the concept of a test-image and set-image. So long as the image on-disk is as expected during a “compare”, the host knows that it can continue to update the lock.

A change in the VMFS heartbeat update method was introduced in ESXi 5.5 Update 2, to help optimize the VMFS heartbeat process which meant there was a significant increase in the volume of ATS commands the ESXi kernel issued resulting in increased load on the storage system. Under certain circumstances, VMFS heartbeat using ATS may fail with ATS miscompare which causes the ESXi kernel to again verify its access to VMFS datastores.

In this case, a heartbeat I/O (1) got timed-out and VMFS aborted that I/O, but before aborting the I/O, the I/O (ATS “set”) actually made it to the disk. VMFS next re-tried the ATS using the original “test-image” in step (1) since the previous one was aborted, and the assumption was that the ATS didn’t make it to the disk. Since the ATS “set” made it to the disk before the abort, the ATS “test” meant that the in-memory and on-disk images no longer matched, so the array returned “ATS miscompare”. When an ATS miscompare is received, all outstanding IO is aborted with host sense 8 (H:0x8 SCSI reset). This led to additional stress and load being placed on the storage arrays and degraded performance.

There are some EMC and IBM arrays which have known issues and recommend disabling the functionality (Use of ATS for vmfs Heartbeat) on all hosts accessing the set of LUNs.
Sample log messages in the vmkernel logs of ESXi hosts and events in vCenter confirming the issue.

In the /var/run/log/vobd.log file and Virtual Center Events, you see the VOB message:

Lost access to volume <uuid><volume name> due to connectivity issues. Recovery attempt is in progress and the outcome will be reported shortly

In the /var/run/log/vmkernel.log file, you see the message:

ATS Miscompare detected between test and set HB images at offset XXX on vol YYY

In the /var/log/vmkernel.log file, you see similar error messages indicating an ATS miscompare:

2015-11-20T22:12:47.194Z cpu13:33467)ScsiDeviceIO: 2645: Cmd(0x439dd0d7c400) 0x89, CmdSN 0x2f3dd6 from world 3937473 to dev “naa.50002ac0049412fa” failed H:0x0 D:0x2 P:0x0 Valid sense data: 0xe 0x1d 0x0.

Disable ATS on vmfs5 and vmfs6 datastores:

esxcli system settings advanced set -i 0 -o /VMFS3/UseATSForHBOnVMFS5

Disable ATS on vmfs3 datastores:

esxcli system settings advanced set -i 0 -o /VMFS3/UseATSForHBOnVMFS3

To review the results of changing options, run this command:

esxcli system settings advanced list -o /VMFS3/UseATSForHBonVMFS3
esxcli system settings advanced list -o /VMFS3/UseATSForHBonVMFS5
You see output similar to:
Type: integer
Int Value: 0 <— Check this value
Default Int Value: 0
Min Value: 0
Max Value: 1
String Value:
Default String Value:
Valid Characters:
Description: Use ATS for HB on ATS supported VMFS3 volumes

Some additional helpful links:!/vsphere-storage/vmware-vsphere-apis-array-integration-vaai-1/atomic-test-set-ats/1 

Options to copy files from VM Guest to Client PC or vice versa

Not many of us use the clipboard option available in vSphere client to copy and paste files across VMs.

I just wanted to share couple of options that can be used other than normal RDP or SMB.

  1. Enable clipboard copy in vSphere Client
  • Log in to a vCenter Server system using the vSphere Client and power off the virtual machine.
  • Select the virtual machine and click the Summary tab.
  • Click Edit Settings.
  • Navigate to Options > Advanced > General and click Configuration Parameters.
  • Click Add Row.
  • Type these values in the Name and Value columns:        FALSE       FALSE

To enable the same across all VMs on a hosts.

  • Log in to the ESX/ESXi host as a root user.
  • Take a backup of the /etc/vmware/config file.
  • Open the /etc/vmware/config file using a text editor.
  • Add these entries to the file:

                vmx.fullpath = “/bin/vmx””FALSE””FALSE”

  • Save and Close the file.

The VM has be restarted for the changes to take effect.

2) Copy-VMGuestFile

This can used with powercli (32 bit) and it’s very helpful if you want to move some file from across VMs.

Especially for the ones which are in DMZ and Clipboard or RDP is disabled for security reasons.

Copy-VMGuestFile -Source c:\test.txt -Destination c:\temp\ -VM myVM -GuestToLocal -HostUser root -HostPassword pass1 -GuestUser user -GuestPassword pass2

Make sure you are connected to vCenter using the FQDN.

The Copy-VMGuestFile uses the vSphere API ad uses the below procedure.


  1. A vSphere Web services client program calls a function in the vSphere API.
  2. The client sends a SOAP command over https (port 443) to vCenter Server.
  3. The vCenter Server passes the command to the host agent process hostd, which sends it to VMX.
  4. VMX relays the command to VMware Tools in the guest.
  5. VMware Tools has the Guest OS execute the guest operation.

The same cmdlet can be used to copy files from clients to VM.

Copy-VMGuestFile -VM myVM -LocalToGuest -Source “C:\temp\test.txt” -Destination “c:\test” -GuestUser “Guestaccoutdetails” -GuestPassword “passowrd”