What HA Datastore Heartbeating and how to use it?

When the master host in a vSphere HA cluster can not communicate with a slave host over the management network, the master host uses datastore heartbeating to determine whether the slave host has failed, is in a network partition, or is network isolated. If the slave host has stopped datastore heartbeating, it is considered to have failed and its virtual machines are restarted elsewhere. vCenter Server selects a preferred set of datastores for heartbeating. This selection is made to maximize the number of hosts that have access to a heartbeating datastore and minimize the likelihood that the datastores are backed by the same storage array or NFS server.

In almost every scenario you want to use datastore heartbeating. This is an important mechanism to both protect virtual machine workloads as well as preventing failover from occuring due to a false positive. However, there are situations where you may not want to use datastore heartbeating. One example that comes to mind is a cluster of VMware ESXi Servers that host a critical application but only requires one LUN due to either its size or other factors. However, due to either licensing or the importance of the application you want to dedicate those workloads to a specific cluster that exist to only serve that application. In that scenario with only one datastore vSphere will display a warning. To resolve this you must alter the datastore heartbeat settings for the vSphere cluster.

Steps to configure Datastore Heartbeating

Step 1: Log in to vCenter and view the cluster. You will see a similar warning to the below.

Step 2: Right-click the cluster, click Edit Settings, select vSphere HA, and then Advanced Options.

Step 3: Under Option, add an entry for das.ignoreInsufficientHbDatastore and set it's value to true.

Step 4: Right click each host in the cluster with the warning and select Reconfigure for HA.

Related Posts


How to Install the VMware Tools on CentOS 6

It is very important that you install VMware Tools in the guest operating system. With the VMware Tools installed VMs support significantly faster performance, time synchronization, and other enhanced features. Below are the steps to Read more…


VMware SRM: The guest operating system ‘centos64Guest’ is not supported

Recently, I ran a test of a SRM Recovery Plan for a new set of Linux VMs I inherited. The first test didn’t go so well and returned the error “Error – The guest operating Read more…


Provisioning error occurred for Machine (VM Name): Refit operation refresh failed

Recently I encountered some VM refresh issues in View I felt would be helpful to share. Using the View administrator I attempted to refresh a couple of linked clones manually. Some of the refresh operations Read more…