New to iPXE - what could be wrong with DHCP server and/or router?

[dirovame]

Hello,

I am a complete newbie to iPXE/CloneZilla. I will try my best to describe the problem I have.

I'm been given the task to upgrade the OS on specific-use appliances running old version of Ubuntu 10.04 to Ubuntu 14.04. We have thousands of these appliances and manually doing this is out of the question. I was given a tool built by one of our vendors that would allow me to do this remotely.

The server/tool handed to me leverages iPXE and it runs Ubuntu 14.04 LTS. Was told for process to work two things are necessary: DHCP server needs to be setup and PortFast should be enabled on all switches. This is all complete.

Here's the issue: I am able to reimage one appliance (that, let's say is on VLAN 404) using the server. As soon as I attempt to reimage a second appliance that exists in the same VLAN I always run into these errors.

modprobe: module vesafb not found in modules.dep
BusyBox v1.21.1 (Ubuntu 1:1.21.0-1ubuntu1) built-in shell (ssh)
/bin/sh: can't access tty: job control turned off
(initramfs)

When reimaging another appliance that say exists on VLAN 450, the first one is always successful and every subsequent attempt to reimage other appliances in the same VLAN fails with same above error. I've noticed this pattern when testing in 15 different VLANs.

The error always appears when the appliance is attempting to Start Clonezilla. I'm not even sure if this is even a question with CloneZilla or with how iPXE works.

My network resource is not sure what the problem is.

Any help is highly appreciated.

Thank you!