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Configure a custom iPXE script to boot your server from the OVHcloud API

Stephanie R.
Updated

NOTE: This article is intended for experienced users who have at least basic knowledge about Preboot Execution Environment (PXE) and its implementation being used at OVHcloud: iPXE.

In the OVHcloud Control Panel, it is possible to specify a boot mode among a predefined list: primary disk or rescue.
With the OVHcloud API, you can define custom scripts.

A custom script can be useful in the following use cases:

  • You are using a volatile OS that you don't want to install on disk, and that remains only in memory.
  • You have a multi-cloud strategy and one of the other cloud providers you use doesn't offer the OS you want to install, nor does it offer an alternative solution such as Bring Your Own Image.
  • You want a standard installation process whatever the cloud provider is, so you have built your own rescue installation image to fully manage the complete OS installation of your dedicated server.

 

Requirements

NOTE: Restarting a dedicated server can cause an outage of all services that only depend on this dedicated server.

 

Instructions

Generate an iPXE script for your dedicated server

Change server iPXE script

PUT /dedicated/server/{serviceName}

Specify your script within the bootScript attribute directly.

 

Get the server iPXE script

GET /dedicated/server/{serviceName}

You can see your script within the bootScript attribute.

For example, the following script chainloads the netboot.xyz boot menu:

{
   "noIntervention": false,
   "name": "nsXXXXXXX.ip-XXX-XXX-XXX.us",
   "rack": "SXXXBXX",
   "commercialRange": "fs",
   "os": "debian11_64",
   "rootDevice": null,
   "rescueMail": null,
   "linkSpeed": 1000,
   "bootScript": "#!ipxe\necho Chainloading netboot.xyz\ndhcp\nchain --autofree https://boot.netboot.xyz\n",
   "reverse": "nsXXXXXXX.ip-XXX-XXX-XXX.us",
   "state": "ok",
   "ip": "XXX.XXX.XXX.XXX",
   "bootId": null,
   "newUpgradeSystem": false,
   "datacenter": "sbg3",
   "professionalUse": false,
   "supportLevel": "pro",
   "serverId": 123456,
   "powerState": "poweron",
   "monitoring": false
}

You can now reboot your server, and it will use your iPXE to boot.

 

Changing boot modes

You can now switch back to disk or rescue boot from the OVHcloud Control Panel (see our guide on Activating and using rescue mode), or the OVHcloud API.

Switch to disk

PUT /dedicated/server/{serviceName}

Specify 1 in the bootId attribute.

GET /dedicated/server/{serviceName}

You can now see that the attribute value bootScript is null.

 

Go further

iPXE - open source boot firmware

For more information and tutorials, please see our other Dedicated Servers support guides or explore the guides for other OVHcloud products and services.

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