Category: vCenter

vCenter 6.5 tip: Enabling vCenter HA? do so when things are quiet in your environment

Picked up this useful tip from the vCenter Server HA performance and Best Practices guide (see –¬†

Will see on Pg 23 it will refer to the fact that:

“As a best practice, it is highly recommended to pick a time period with a very light workload to enable VCHA. Otherwise, the newly cloned Passive node PostgreSQL DB could lag behind too much and not be able to catch up with the Active DB due to transaction logs on the Active DB getting purged on the Active node. We are working on adding archivelog support to address this issue in upcoming releases.”

Sensible advice, might mean weekend work for some folk mind ūüė¶


VCenter tip: Enhanced Link Mode and how to enable

Enhanced Linked Mode enables a single point of management across all vCenter Servers in the same vSphere Single Sign On (SSO) domain. Easier admin results as can look after multiple vCenter instances from one pane.

To enable Enhanced Linked Mode, follow these steps:

  1. Ensure that Enhanced Linked Mode requirements are met:
    • All PSCs are in the same vSphere Single Sign On domain.
  2. Deploy PSC and vCenter Servers in a supported deployment topology.

Once all enabled all the inventories from your vCenter environments in the same SSO domain will be linked together in Enhanced Link Mode. Can then access all from the vSphere web client (unfortunately not available in the traditional client :()


VCSA Tip: how to fix the “Error: VPXD must be stopped to perform this operation” message

Oftentimes will see the above message when working within the VCSA appliance and needing to carry out admin functions.

To resolve:

i) Logon to the console eg https:<appliancename:5480 and enter your administrator id and password

ii) Click vCenter Server after logon

iii) Click the Summary tab

iv) Click on the Stop button to stop the server component

If the above doesn’t work (in most instances it should) then do the following:

i) Connect to the appliance’s console using putty or your SSH client of choice

ii) After logon type # chkconfig and check if vmware-vpxd is on or off

iii) if showing on you can stop it by entering # service vmware-vpxd stop

iv) When you need to start the server again simply enter # service vmware-vpxd start


vCenter quick tip: Need to troubleshoot SIOC issues? here’s how to enable logging

In vSphere infrastructure storage as you probably know, I/O usage of virtual machines can be controlled by Storage I/O control (SIOC). In event of hitting issues good to enable logging to help resolve issues.

Here’s how to enable¬†SIOC logging from the vSphere client:

  1. Enter your vSphere web client URL and log in.
  2. Click Host and Configuration tab.
  3. From the left-hand side column named Software, click on Advanced Settings.
  4. In the parameters list, click into the Misc section and select the Misc.SIOControlLogLevel parameter.
  5. By default, it is set to zero, which means it is disabled. To log everything, set the value to 7.
  6. Enter 7 in the field and click OK to close the pop-up box.
  7. You will now be able to see the logs in /var/log/vmkernel.

Happy troubleshooting ūüôā

vCenter DRS tip: Anyone used the cool online tool VM Resource and Availability Service?

If ever you encounter DRS issues in any of your vCenter cluster environments may need to get a DRS dump file generated in order to troubleshoot the issue. The file itself is called drmdump and contains various calculations¬†that DRS uses to measure possible benefits to migrate VM’s.

Locations for these files:

vCenter Server Appliance


Full Windows vCenter instance

%ALLUSERSPROFILE%\VMware\VMware VirtualCenter\Logs\drmdump\clusterName.

What’s really cool is VMware also offers an online tool called VM Resource and Availability Service (URL:, telling you which VMs can be restarted during the ESXi host failures. Simply ¬†upload your metric file in order to give you the results. Really helpful in¬†simulating the failure scenarios that can occur.



vCenter tip: housekeeping tips for your vCenter Server Database

If using a small/medium vCenter setup may well be using a Postgres database to get you by. Good to run a check on it from time to time. Standard operations include:

  • Performing regular backups
  • Monitoring log growth and compact when needed

Although as part of its own day-to-day operations space is automatically reclaimed sometimes you may run into situations where you need to manually reclaim space. To do:

Step 1. Log in to the VMware vCenter Server Appliance as root using SSH (putty) or directly at the console.

Step 2. To stop the vCenter service: service vmware-vpxd stop

Step 3. To find out the database password:

cat /etc/vmware-vpx/embedded_db.cfg | grep PASSWORD

Step 4. To get an idea of storage availability run # df -h

Step 5. In the results of the previous command, locate the /storage/db row to determine the amount of space used by the database.

Step 6. Enter this command to run the Vaccum command:

sudo -u postgres /opt/vmware/vpostgres/1.0/bin/vacuumdb -a -e -v -f -U postgres > /tmp/vacuumdb.log

Step 7 The Vaccuum command will prompt you to enter a database password for each of the 5 associated databases, postgres, template0, template1, VCDB and ssodb. At each prompt, provide the password obtained in Step 3.

Step 8. Use this command again to verify that the space used by the database has decreased: df -h


The status of your VMware Postgres database at Home > Administration > System Configuration > Services. Select the VMware Postgres service in the list of services and use the information in the center pane to verify the Health is Good and the State is Running.

From here you can also, you can use the Actions dropdown to stop and restart the service.