What should we know before installing ESXi

If this is your first time installing ESXi, I bet you would be doing it in a virtual machine. There are several guides out there on the internet. VMware supports installing ESXi on a virtual machine for non-production use.

If you are going to install ESXi at work and your company is already using VMware, talk to your team for their install guide. If they don’t have one, take the opportunity to create one.

Install Method
Which install method are you going to use? The options are

  • Interactive ESXi installation
  • Scripted (Kickstart) ESXi installation
  • Auto Deploy ESXi installation
  • Customizing installations with ESXi Image Builder CLI

Via Methods for installing ESXi 6.0 (2109708)

Install Media
In most cases except Auto Deploy, you will need to boot the server with an ESXi install media. The options are:

  • Inserting the CD/DVD in to the DVD-ROM drive in the server
  • Plugging in a bootable USB device
  • Mounting an ISO remotely

Via http://kb.vmware.com/kb/2109708

Is anyone still using an optical media for OS installation these days? Even for a server without lights out management such RSA, iLO, DRAC etc. , I think USB would be the preferred choice.

Which ISO to download

Some server vendors provide a custom ISO which comes with all necessary drivers. If you find a custom ISO for your server, you should use that. Otherwise, grab the “ESXi ISO image (Includes VMware Tools)”

Supported Hardware
These are the minimum requirements

  • A host with 2 or more CPU cores.
  • A 64-bit x86 processor released after September 2006. For a complete list of supported processors, see the VMware Compatibility Guide.
  • The NX/XD bit for the CPU must be enabled in the host BIOS.
  • To support 64-bit virtual machines, support for hardware virtualization (Intel VT-x or AMD RVI) must be enabled on x64 CPUs.

via Best practices to install or upgrade to VMware ESXi 6.0 (2109712)

For production use, make sure your hardware is in VMware Compatibility Guide. Before the hardware is procured, it would have been verified. But may be not for some reason such as the hardware was procured for a different purpose. If it is not a certified hardware, it may work but VMware Support will not help you.

For home lab, Mac Mini and Intel NUC are popular. For learning, it is common see see many running ESXi on VMware Workstation or Fusion on their laptops with lots of memory ( 8 to 16 Gig).

Install Device

For production environment, this is an important information to collect before you start. The options are

  • Local disk
  • SD card
  • USB drive

ESXi 6.0 requires a minimum of 1GB for boot device. When booting from a local disk, SAN or iSCSI LUN, a 5.2GB disk is required but 6GB is recommended.

The installer will show which are local and remote. SAN LUN will be local. Local disk, SD card and USB drive will be local. It is very easy to identify the type of storage from the display name and its size.

If you are building a new host for an existing cluster, check how the existing hosts in the cluster are built. Mostly likely, the new host you are building is configured the same way.

Host specific Information
After the installation is over, to bring the host online on the network you will need to know the following

  • Hostame with FQDN
  • IP Address
  • Netmask
  • Default Gateway

If the NICs for Management are configured to see multiple VLANs (trunk mode), you will need to know the VLAN ID of the host IP subnet.

Though not required to bring the host online, I recommend to configure NTP and DNS resolver at install time. Hence gather these information too.

  • Nameserver
  • NTP Server

Post Install Configuration
This is where you fine tune and polish the host for your environment. Do you keep IPV6 on? Do you enable or disable certain VMKernel features. Do you use password based or key based ssh login for root.

This could be achieved by a series of commands that you run on the ESXi console. If you are are doing scripted install, you can add it to the post install section in your kickstart file. If the settings are going to be the standard in your environment, it is best scripted. Be a lazy admin. At the minimum, have the set of commands ready.

Network configuration
Installing ESXi is easy. Configuring the network is where new admins might struggle. Refer to your company standards. How are you going to split the NICS? A possible configuration is two vmnics for Management, vMotion and NAS. A second set of two vmnics for Guests. This is where your networking knowledge, especially understanding of VLAN, access mode vs trunk mode, will help. If the vmnics are connected to an access port, you don’t tag VLAN ID in the host. If the vmnics are connected to trunk ports, you will need VLAN tagging at the host level.

If you use 10G NIC, are you going to enable Jumbo Frames? Enabling Jumbo Frames on one end is not enough. It has to be enabled end to end.

What is your company’s standards for VMware networking? The options are

  • Good old Virtual Standard Switch (VSS)
  • Cisco Nexus 1000v Distributed Switch
  • VMware Distributed Switch (VDS)

Post Install verification
Are the Management and Guest networking validated? Can you vMotion a VM into the new host. When you add the host into vCenter, you will be asked to assign a license to choose later. If you choose later, you will need to assign before the evaluation period runs out.

If you are building a whole new cluster, ensure that DRS and HA are working correctly.

Syslog and Netdump
If the host is installed in an SD card or USB media, you will need to configure the host to send logs and dumps to remote syslog and netdump server. The host will report that there is no persistent storage for the logs. The logs will disappear after a reboot.

If the install media is a local disk or SAN lun, if I find it helpful to name it as hostname-local or hostname-boot. It is easy to tell which is which in vSphere client storage view. Find out the naming standard in your environment and ensure compliance. It will help you and your team.

If you are adding a new host into an existing cluster, ensure you add the NFS datastores with the same name as other hosts in the cluster. If the cluster uses SAN luns, chances are they are already presented to the new hosts. A refresh or rescan would be enough to detect them, if not already.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s