Autoinstall physical NSX Edge with custom passwords

Background

Setting up NSX Edge in an automatic way with a custom password is a good idea because by default you get a default password that needs to be changed at first login. If you're planning on using an extra strong password, setting it through iDRAC (or similar) can be a bit awkward. If you're using a non-english keyboard layout (like me) it can be even more non-trivial to hit the correct special characters.

Problem

1. We had a problem getting the physical Dell R640 server with Mellanox 25GbE nics to boot from PXE. It would say "Booting from PXE Device 1: Integrated NIC 1 Port 1 Partition 1 Downloading NBP file... NBP File downloaded successfully. Boot: Failed PXE Device 1: Integrated NIC 1 Port 1 Partition 1 No boot device available or Operating system detected. Please ensure a compatible bootable media is available."

2. VMware has provided us with a nice 19 step document that guides us through the needed steps for setting up everything we need. The optional step 16 of setting a non-default password is however a bit misleading (probably referring to an older version of NSX?) and doesn't quite work.

Solution

1. In order to get the physical server to PXE boot we had to change the boot mode from UEFI to BIOS.

2. I had a case open for months without a resolution. In the end I started studying the Debian manuals (that the NSX Edge installer is based upon). I eventually found a working solution. It turned out that adding the following commands to preseed.cfg right after the "di passwd/root..." line gave a working config:

d-i preseed/late_command       string \
        in-target usermod --password 'insert non escaped password hash here' root;\
        in-target usermod --password 'non escaped password hash' admin

You will need to create the password hash using mkpasswd -m sha-512 as described in the original 19 step document.