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HA warning in VMWare

Medium Priority
Last Modified: 2012-08-20

I have a VMWare 5 setup with 3 servers in the cluster. The system has been operating fine for months but currently my exchange vm has start rebooting nightly due to Vspheres HA.

Nothing changes in the setup that i'm aware of but now every morning i come in and  vSphere has an alarm related to HA  "Vsphere HA Virtual Machine monitoring action" and the exchange box has been restarted. the exchange box itself doesnt show any sign in the logs of service failure etc so I'm sure why HA is deciding to reboot the server every night.

Any advice would be helpful

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BusbarSolutions Architect

any alerts, HA will be initiated if the host is isolated or failed, any error or alerts ?!
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Expert of the Year 2017

check if there has been any change of networking?

is this the only VM, which is restarting?

Check the vmware.log in the VMware folder.


Nothing has changed with regards to networking. Or settings wise within the servers.

The exchange server is the only thing thats restarting, There nothing in the event log to indicate that the exchange server is having an issue. Ha just seems to have decided to restart it every night.

From reading the forums my best guess is that its VM monitoring that causing the issue, the solution seems to be turning off VM monitoring for the specfic VM. My concern with this is that everything was previously working fine until recently.

What is the impact of turning off VM monitoring ?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Expert of the Year 2017

it will not restart VMs, if it lose heartbeat or contact with them!

check the VMware log, outside of the VM, on the datastore, see if that provides a clue.

Odd how only one VMs is affected?

not backing up the VM, using Snapshot Aware application, and VMs is offline for several seconds, causing HA, to restart it!

I would also recommend some good reading around this subject here

VMware vSphere 4.1 HA and DRS Technical deepdive (Volume 1)

By Duncan Epping and Frank Denneman


ISBN-10: 1456301446
ISBN-13: 978-1456301446

Written by Duncan Epping and Frank Denneman, both of whom are Consulting Architects at VMware and are perceived by the industry as Subject Matter experts on VMware High Availability and VMware Distributed Resource Scheduler.
This book zooms in on two key components of every VMware based infrastructure. It covers the basic steps needed to create a VMware HA and DRS cluster, and goes on to explain the concepts and mechanisms behind HA and DRS which will enable you to make well educated decisions. You will get the tools to understand and implement e.g. HA admission control policies, DRS resource pools and resource allocation settings and more.

On Amazon US





on Amazon UK





Available in Europe from


VMware vSphere 5.0 now also available.

Check your HA Settings - make sure that you have the Virtual Machines set not to reboot during loss of connection...  Post back what you see.

Right click the cluster, settings, HA or High Availability....
I believe Ha is set to reboot client machines at loss of connection but isnt this something that i want in the event that the machine becomes unreachable it will be rebooted.
The machine itself shows no signs of issues in the event log that would suggest it has become unreabled there no heavy load or contention at the time of reboot.

I've disabled HA and then re enable and reinstalled VMware tools and the box hasnt reboot last night so may now be sorted

thanks for your input


As per last post this seems to have resolved issue