WilliamLam.com

Can you really deploy the vCenter Server Appliance (VCSA) without DNS and NTP?

by // 12 Comments

The simple answer is Yes. Now, you might be wondering why anyone would want to put themselves through the pain without setting up proper DNS and NTP?

Well, not all environments have the luxury of having either outbound connectivity and/or access to basic infrastructure services like DNS and NTP. This may come as a surprise to some, but there are customers out there that need to operate in very unique and constrained environments. One such example of this is typically from customers that need to deploy vSphere in a "dark site" where local infrastructure services like DNS and NTP are not available.


I recently re-validated this deployment model using the latest vSphere 7.0 Update 3 release running on an Intel NUC 11 which had no outbound connectivity and it was only connected to my laptop, which also had no outbound connectivity or access to DNS or NTP. Since this question recently came up from a customer who was looking to automate this, so I ran through the deployment workflow using the VCSA CLI Installer but this should also be possible with VCSA UI Installer as the same options are supported.

OK, so how do you make this work?

[Read more...]

Is a DNS server still required when using a Static IP for VCSA?

by // 7 Comments

When deploying a vCenter Server Appliance (VCSA), customers have two options for setting up a static network address: using either a hostname (Fully Qualified Domain Name) or just a static IP Address (e.g. no DNS). In the first option when using an FQDN, it should be no surprise that you need to also specify a valid DNS Server which the VCSA UI/CLI Installer will automatically validate both the forward and reverse address. This is the most common deployment model for customers in both production as well as for development environments such as a vSphere home lab.

In the second scenario, where a static IP Address is used, a DNS server is not required because we are NOT using an FQDN for the hostname but rather an IP Address. Having said that, if you have ever used the VCSA UI or CLI, you will find that the DNS Server entry is actually a required field and you can not proceed without providing an address.

VCSA UI Installer:

VCSA CLI Installer:

"network": {
    "ip_family": "ipv4",
    "mode": "static",
    "ip": "192.168.30.151",
    "dns_servers": [
        "192.168.30.1"
    ],
    "prefix": "24",
    "gateway": "192.168.30.1",
    "system_name": "192.168.30.151"
}

As mentioned earlier, we know that it should not be required but currently the VCSA Installer is a bit overly cautious in its pre-checks and does require a value today. This is something that has already been shared internally and the team will be relaxing this requirement in the future.

With that said, this leads us back to the original question posed in the blog title, do we need a valid DNS server when using a static IP for the VCSA?

[Read more...]

How to evaluate vSphere Data Protection without DNS?

by // 15 Comments

A fellow colleague of mine was looking to deploy the latest vSphere Data Protection Advanced (VDP[A]) 5.5 in his lab this past week to check out some of the new enhancements made to VDP and interoperability between other VMware solutions. However, he was unable to move forward with his evaluation due to the mandatory DNS requirement for VDP. I can understand the need for having proper DNS in a production or even a POC environment but for a quick evaluation or home lab it is a bit much. In my opinion I think it is a nice to have but it should not be a mandatory requirement.

As part of the networking settings, VDP assumes that configured IP Address is fully resolvable both forward/reverse lookups and manually adding an entry into /etc/hosts will not work. If you try to move forward in the wizard, you will receive this nice error message.

I decided to look into this as I faced a similar challenge in my personal home lab which does not have a DNS Server due to limited resources unlike my remote home lab which has a proper DNS server running. Though we can not get rid of the DNS requirement since it is part of the VDP code, we can however leverage an application found within VDP to help us. This nifty little application is called dnsmasq which is a lightweight server that provides basic DNS, DHCP & TFTP services for a small network which works great for an evaluation or home lab.

Disclaimer: I have been able to verify basic VDP functionality including a complete VM image backup/restore using the method below. However, it is still recommended that you still have proper DNS configured in your environment for in-depth testing of VDP, especially when evaluating for a production environment.

Step 1 - Deploy the VDP OVA as you normally would and when you specify the network configurations, ensure you set the DNS entry to 127.0.0.1 (loop back address) and then you can power on the VM after deployment.

Step 2 - Once VDP is up and running, SSH into the system using root as username and changeme as the password. We will then need to update /etc/hosts to reflect the IP Address/Hostname of our VDP appliance as well as any others you may want VDP to be able to resolve. In my environment I have the following:

192.168.1.104 vdp.primp-industries.com vdp
192.168.1.103 vcenter.primp-industries.com vcenter
192.168.1.200 mini.primp-industries.com mini

Note: I would also recommend adding your "search" domain into /etc/resolv.conf (e.g. search primp-industries.com)

Step 3 - Next we need to edit the dnsmasq configuration file located in /etc/dnsmasq.conf and add the following entry (replace it with the IP Address you have assigned your VDP appliance):

server=192.168.1.104

Step 4 - Finally we just need to start the dnsmasq service as well as enable it to automatically startup on boot by running the following two commands:

/etc/init.d/dnsmasq start
chkconfig dnsmasq on

Step 5 - To confirm that everything has been configured correctly, we will perform both a forward and reverse lookup of our VDP hostname and IP Address. You can do so by using "nslookup" command or any others such as dig or host. In this example, I will be using nslookup and you will need to run the following two commands (ensure to replace it with your hostname/IP Address):

nslookup vdp.primp-industries.com
nslookup 192.168.1.104

Once you have confirmed both forward and reverse lookups are successful, you can then proceed to configuring your VDP appliance by opening a browser to https://[VDP-ADDRESS]:8543/vdp-configure and proceed with moving forward with the VDP configuration wizard.

Note: Ensure that 127.0.0.1 is shown in the VDP configuration UI for the DNS entry. For hostname, you will need to use the short hostname even though a hostname is officially defined as specifying the FQDN

One of the cool new features that I personally wanted to check out is the new emergency Direct-to-Host Emergency Restore functionality. This feature allows you to restore VM backups in the scenario that vCenter Server is not available and one such use case is when you are using VDP to backup vCenter Server itself which I have been able to successfully test in my home lab.