Information Technology Reference
In-Depth Information
Figure 2.9
Note the diff erences
in the ESXi boot
process when using
Auto Deploy versus
a traditional instal-
lation of ESXi.
Of course, there are some additional concerns that you'll need to address should you decide
to go this route:
◆
The image proi le doesn't contain any ESXi coni guration state information, such as virtual
switches, security settings, advanced parameters, and so forth. Host proi les are used to
store this coni guration state information in vCenter Server and pass that coni guration
information down to a host automatically. You can use a deployment rule to assign a host
proi le, or you can assign a host proi le to a cluster and then use a deployment rule to join
hosts to a cluster. We'll describe host proi les in greater detail in Chapter 3.
State information such as log i les, generated private keys, and so forth is stored in host
memory and is lost during a reboot. Therefore, you must coni gure additional settings
such as setting up syslog for capturing the ESXi logs. Otherwise, this vital operational
information is lost every time the host is rebooted. The coni guration for capturing this
state information can be included in a host proi le that is assigned to a host or cluster.
◆
In the Auto Deploy Stateless mode, the ESXi image doesn't contain coni guration state and
doesn't maintain dynamic state information, and they are therefore considered
stateless
ESXi
hosts
. All the state information is stored elsewhere instead of on the host itself.
Ensuring Auto Deploy is Available
Author Nick Marshall says, “When working with a customer with vSphere 5.0 Auto Deploy, we had
to ensure that all Auto Deploy components were highly available. h is meant designing the infra-
structure that was responsible for booting and deploying ESXi hosts was more complicated than
normal. Services such as PXE and Auto Deploy and the vCenter VMs were all deployed on hosts
that were not provisioned using Auto Deploy in a separate management cluster.
As per the Highly Available Auto Deploy best practices in the vSphere documentation, building a
separate cluster with a local installation or boot from SAN will ensure there is no chicken-and-egg
situation. You need to ensure that in a completely virtualized environment your VMs that provision
ESXi hosts with Auto Deploy are not running on the ESXi hosts they need to build.”
