ESXi - Install from USB and To a USB

Install from USB

Instructions
Format USB drive as FAT32.
Download Syslinux. http://www.kernel.org/pub/linux/utils/boot/syslinux/
Run win32/syslinux -f -m -a usbdriveletter: or win64/syslinux64 -f -m -a usbdriveletter:
Copy contents of ESXi ISO to USB drive.
Rename isolinux.bin and isolinux.cfg to syslinux.bin and syslinux.cfg
Create file on USB drive called ks.cfg. A simple one is listed below. For more information on this see pg. 36 of the documentation here: http://www.vmware.com/pdf/vsphere4/r41/vsp_41_esxi_i_vc_setup_guide.pdf
start ks.cfg
vmaccepteula
rootpw password
autopart --firstdisk --overwritevmfs
install usb
network --device=vmnic0 --bootproto=dhcp
end ks.cfg
Edit syslinux.cfg - under the ESXi Installer line, add "ks=usb" after vmkboot.gz in the "append" line, like so:
append vmkboot.gz ks=usb --- vmkernel.gz --- sys.vgz --- cim.vgz --- ienviron.vgz --- install.vgz
You need to do these two things if you downloaded the latest version of Syslinux, something past version 4. Otherwise you will get an error to the effect of "not a valid com32 image" or something when you try to boot.
Copy %syslinux%/com32/mboot/mboot.c32 to USB drive (overwrite)
Copy %syslinux%/com32/menu/menu.c32 to USB drive (overwrite)

Install to USB
http://www.techhead.co.uk/installing-vmware-esxi-4-0-on-a-usb-memory-stick-the-official-way

VMware VMA (Management Assistant for ESXi) and adding hosts and VMA to AD - resxtop limitiations

http://www.virtuallyghetto.com/2010/05/getting-started-with-vma.html - (Getting started guide)

http://www.simonlong.co.uk/blog/2010/05/28/using-vma-as-your-esxi-syslog-server/ - Setting up a syslog srver

Bulk add hosts to the vMA http://www.virtuallyghetto.com/p/vmware-vma-vima.html 

name the vMA "domainjoin-cli name <Computername>"
Join the Domain "domainjoin-cli join <username>"

Add the user to the list of sudoers on the vMA
sudo nano /etc/sudoers
at the bottom of the file
add the following
%domainname//domain^admins ALL =(ALL)  ALL

 This allows the users within the domain admins group to sudo within the VMA




To allow domain admins to log on locally and act as root on the ESX servers , the group ESX Admins must be created in AD , add Domain Admins to this group.

The ESX server periodically check for the existence of this group , if it is present it adds it to the administrators group on the ESX server

We can now log on to the VMA box with our AD account and the ESX servers with our AD account.
unfortunately  within the VMA the ESX servers are still configured to use fastpass authentication
( vifp listservers -l )

Run the following for each of the hosts to change them to use adauth instead of fpauth
(fast pass authentication)

vifp reconfigure esxhost.domainname --authpolicy adauth

Each time you logon to vMA set the target as the virtual center and you will not be prompted for your credentials when running commands against the hosts

vifptarget --set <vcentreserver>


Your prompt should be as follows
[domain\username@vmahostname ~][vcenter.domainname]$
you should be able to issue vicfg-nics -l --vihost esxserver and not be prompted for credentials

Resxtop

a limitiation of resxtop is that each time you want to switch between servers you will need to re-enter your credentials, there is no secure way around this.
It is possible to pipe your password in clear text
echo "password" | resxtop --server xxx --username user -b -d 15 -n 9 | ....