How important is DNS?

[idiriasl]

Hi,

I am following the Scott Lowe's book "Mastering VMware" to study about VMware Sphere. Nevertheless, I have a question about the DNS importance that it is stressed on the book. Is it really necessary to include a DNS to make VMware Sphere work properly? What happens if the DNS fails? Does this mean I have to create yet another DNS machine and a replication of it to provide fault tolerance? (perhaps virtualized both of them)...

Thanks in advance,

Jose.

[idle-jam]

DNS is important for VMware HA to work during vSphere4, however in vSphere5 it does not require DNS to restart a failed VM on another host.

[idiriasl]

Uhmmm, interesting. The thing is that during the vCenter installation (5.0) it says that FQDN is required for some advances features to work... should I get concerned about it?.

Thanks!

[kruddy]

Depending on how large of an environment you have, you could probably get around the DNS requirements by modifying host files on the systems.

That certainly is not a recommended, nor ideal situation though.

A KB article about it: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100373...

[mcowger · Accepted solution]

DNS is not required anymore for HA to function, making it easier for vCenter to survive large scale failures)

However, it is still required (as per the vCenter docs you saw) for other operations and setup.

You need DNS.  End of story.

[Josh26]

Install the DNS-Server service on your vcenter machine. Create a private zone for your ESXi hosts and the vcenter server. At this point the problem goes away.

You can survive without DNS, in that you can survive withour vcenter for a period should it go down.

Even though vSphere 5 now functions without DNS, I really wish it didn't. It's not hard to setup DNS correctly, and it means everything else falls into place.

[idiriasl]

Thanks a lot for your responses, clear and concise. It is clear that I MUST install a DNS.

Cheers!,

Jose.