Question
How do I specify a server should boot from disk instead of the network in OVH?
Answer
The netboot facility must be configured in the OVHcloud Control Panel
Next, you must connect to the OVH Control Panel
Go to the Bare Metal Cloud section of the interface, Dedicated Servers on the left-hand column, then select the server in question from the list.
In the tab Server Status, section General Information, click on Edit on the line labeled 'boot'.
Then select the option to 'Boot from hard disk', click 'Next' and finally, click 'confirm'.
OVH has some further information on that here.