VMware ESXi HA and DNS

[WillGreen]

I am currently evaluating VMware on a set of blades with ESXi. I have configured a pair of NICs to form the management network and enabled VMotion on them. VMotion works fine between all the hosts both manually and with DRS.

However I'm not sure how I should set up HA, attempting to turn on HA on my test cluster fails because the hostname and IP don't match. The dedicated management network doesn't have a DNS server as it's just the blade servers and the blade chassis switches. I have manually assigned each blades management IP via the ESXi set up screen on each physical host.

• Is there any reason HA can't use IP addresses?

• If I have to use names for resolution, can these be configured in /etc/hosts when using ESXi?

I have attached a screenshot showing the network configuration of one of my hosts (VMotion is enabled on the 'Management Network').

If you have any experience with a similar set up it would be much appreciated.

Thanks,

Will

[djciaro · Accepted solution]

you need to place the FQDM and IP address of all ESX servers in the cluster in the host file on each ESX:

1. Do not remove the following line, or various programs

2. that require network functionality will fail.

127.0.0.1 localhost.localdomain localhost

SERVER IP ADDRESS SERVER NAME

SERVER IP ADDRESS FQDN SERVER

e.g.

192.168.1.12 myserver.mycompany.com

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[benma]

Hi,

yep its possible to run HA without DNS.

Edit your hosts files on ESX and the vCenter Server like the following:

10.1.1.1 esx1.domain.local esx1

10.1.1.2 esx2.domain.local esx2

10.1.1.3 vc1.domain.local vc1

[djciaro]

p.s.

In order to be able to modify the hosts file you will need to enable access via SSH

http://www.vm-help.com/esx/esx3i/ESXi_enable_SSH.php

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[WillGreen]

I'll give enabling ssh a go.

Thanks

[benma]

You can change the file by altering the file from the outside like winscp

or access the local console...

Press Alt+F1

type 'unsupported' and hit enter

now you can login with root

[benma]

djciaro why are you typing so fast?

[djciaro]

and I thought I typed slowly

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[WillGreen]

Is there any supported way to update /etc/hosts on esxi? Seems like something VMware should allow.

[benma]

Without ssh enabled or the console I don't see any possibility of editing the Hosts file

[Dave_Mishchenko]

You can do this with vifs from the RCLI - http://www.vm-help.com/esx/esx3i/esx_3i_rcli/vifs.php.

[WillGreen]

Thanks. This worked.

[WillGreen]

Follow up to this. Using /etc/hosts didn't work well. I switched to using DNS and everything worked much more reliably. Based on my experience I wouldn't recommend using HA without DNS.