VCP 5 – Objective 1.2 – Install and Configure VMware ESXi

Perform an interactive installation of ESXi

Installation is very similar to that of 4.1.  Can mount installer to a CD/DVD or USB Drive.  Can also PXE boot the installation.

Deploy an ESXi host using Auto Deploy

Auto Deploy uses a PXE boot infrastructure in conjunction with vSphere host profiles to provision and customize that host.  No state is stored on the hosts (stateless).  The state is managed by the Auto Deploy server.

Image State

  • executable software that runs on ESXi host.
  • stored in image file that is created with Image Builder power CLI.

Configuration State

  • All configuration options for the ESXi host
  • Stored in host profiles in the vCenter.  Often drafted from a template host.

Dynamic State

  • Run time stats from the running ESXi host.
  • Stored in hosts memory.  All is lost during a reboot.

VM State

  • Virtual Machines

Essentially images are stored on the auto deploy server, then configuration is pushed down through host profiles as well as answer files.

Configure NTP on an ESXi Host

Configured from the vSphere Client (configuration tab) or with vMA and vicfg-ntp.  Pretty simple.

Configure DNS and Routing on an ESXi Host

Can select either manual or automatic DNS.  Automatic is default.  If environment doesn't have automatic DNS you can manually specify hostname, primary and secondary DNS server(s), and DNS suffixes.  Done through vSphere client, the DCUI, or through vicfg-DNS??

Can add and remove routes using vicfg-route.  Only one gateway can be specified for all port groups.

Enable/Configure/Disable hyperthreading

Configuration->Processors->Properties – must be enabled within the BIOS first, some BIOS will call it Logical Processor while others call it Enable Hyperthreading.

Be very wary about using hyperthreading with CPU affinity.  A core that is hyperthreaded will have 2 logical processors (0 and 1), so if you pin one VM to 0 and another to 1, you will essentially have both VMs pinned to the same physical core which could result in unexpected performance results depending on the usage of the VMs.  

Enable/Size/Disable memory compression cache

Memory compression is used to improve VM performance when you have memory overcommitment and is enabled by default.  ESXi will attempt to compress memory pages that can be sized down to 2kb.  By default, ESXi will use 10% of the allocated memory to the VMs on the host for memory caching, but can be changed using the advanced options below.

Must modify host advanced settings – Mem.MemZipEnable = 1 – enable or disable memory caching.

Must modify host Advanced Settings – Mem.MemZipMaxPct = (value specified in percentage between 5 and 100)

License an ESXi host

Can add license to a host through vCenter Server with the standard licensing techniques, or by connecting directly to the host with the vSphere client.

Licenses are based per socket with a vRAM entitlement.

If a license expires, you will no longer be able to power on VMs on that host.  Same goes for if you are over your pooled vRAM entitlement.

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