Missing documentation on BYOI images creation about docs HOT 8 OPEN

Hello @NightTsarina, have you read this documentation https://docs.ovh.com/gb/en/dedicated/bringyourownimage/ ?
There is a sub-part about API usage that may be helpful for you to work on automation.
Feel free to ask our community for help on https://community.ovh.com/en/.
Best,
The OVHcloud Guides Team

from docs.

Hello @NightTsarina, have you read this documentation https://docs.ovh.com/gb/en/dedicated/bringyourownimage/ ? There is a sub-part about API usage that may be helpful for you to work on automation. Feel free to ask our community for help on https://community.ovh.com/en/. Best, The OVHcloud Guides Team

Hi!

Yes, I have checked that doc and also the community pages, but it does not say anything about how to create the image. I know how to upload and use the image, but where do I find an image to use?

from docs.

Hi @NightTsarina
The purpose of the bring-your-own-image feature is to let customers use their own image, usually custom ones or images provided on distributions websites such as Ubuntu, Red Hat, etc. We don't provide any tool to create or customize an image.
I'm sorry the documentation team won't be able to give you more guidance. I suggest you create either a support ticket or a new thread on the community pages, so that the community can help you with your use case.
Best,
The OVHcloud Guides Team

from docs.

If your request is to find the ISO of the OS you want to install and generate a custom image in qcow2 format, we currently don't have a documentation to address it but we're thinking about it.
Best,
The OVHcloud Guides Team

from docs.

Right, that is the problem. I have an ISO that has an interactive installer, but that won't work here. I can convert that to qcow2, but that won't work, because it requires user intervention.. So what I would like is to know what does the OVH system expect from that image and how is it deployed into the server... I have not been able to find any info at all about that.

Maybe you are just running the qcow2 image inside QEMU, and assuming it will automatically install the system? That'd be great, but I'd need to know at least a bit about the runtime environment and how I can pass parameters or configuration to it, so I can create the scripts to drive the install..

On the other hand, the fact that you seem to be managing partitions independently tells me that maybe you are just DD-ing the image onto the harddrive, so then what I need to prepare is just a snapshot of a running system instead of an installer...

These are the kind of questions that I think need to be answered in the documentation so sysadmins can build on top of your great service.

Hope this clarifies my request. Thanks again

from docs.

Hi,
Maybe the documentation is lacking an introductory sentence. BYOI expects an image of your disk containing the OS.

On the other hand, the fact that you seem to be managing partitions independently

We do not touch partitions apart from the configdrive one which we create if your image doesn't contain one. Expanding partitions and filesystems should be handled by cloud-init which you are strongly encouraged to use.

maybe you are just DD-ing the image onto the harddrive, so then what I need to prepare is just a snapshot of a running system instead of an installer...

Yes, that's the general idea. Either you provide a raw image of your disk that will get copied bit-for-bit to the first disk of the server, or you provide a qcow2, in which case it will be converted to raw and then copied to the disk.

You could start by creating a qcow2 from an installed server with qemu-img convert -f raw -O qcow2 -c /dev/sda image.qcow2 . If you don't want to use cloud-init at first, make sure your network configuration will work with DHCP and varying interfaces names.

from docs.

Hi, Maybe the documentation is lacking an introductory sentence. BYOI expects an image of your disk containing the OS.

Ah, I see, this is a key piece of information I was missing!

We do not touch partitions apart from the configdrive one which we create if your image doesn't contain one. Expanding partitions and filesystems should be handled by cloud-init which you are strongly encouraged to use.

maybe you are just DD-ing the image onto the harddrive, so then what I need to prepare is just a snapshot of a running system instead of an installer...

Yes, that's the general idea. Either you provide a raw image of your disk that will get copied bit-for-bit to the first disk of the server, or you provide a qcow2, in which case it will be converted to raw and then copied to the disk.

Gotcha. I suppose then there is no way to configure arbitrary partitioning schemes before the image is copied? I found the OVH partitioning definition a bit restricted. For example, I usually create only 2 partitions on each drive: one for /boot and another for luks encryption + LVM, and then create multiple LVMs with different sizes depending on configuration.

You could start by creating a qcow2 from an installed server with qemu-img convert -f raw -O qcow2 -c /dev/sda image.qcow2 . If you don't want to use cloud-init at first, make sure your network configuration will work with DHCP and varying interfaces names.

Excellent, thanks for this information! I think just adding this paragraph to the documentation would be a huge help for OVH customers.

from docs.

I suppose then there is no way to configure arbitrary partitioning schemes before the image is copied? I found the OVH partitioning definition a bit restricted. For example, I usually create only 2 partitions on each drive: one for /boot and another for luks encryption + LVM, and then create multiple LVMs with different sizes depending on configuration.

The partitions present on your image are left untouched when it is copied to disk. If you want to change that at boot, cloud-init can do it.

I think just adding this paragraph to the documentation would be a huge help for OVH customers.

Yeah I will discuss this with my colleagues. You're also welcome to make a PR modifying https://github.com/ovh/docs/blob/develop/pages/cloud/dedicated/bring-your-own-image/guide.en-gb.md if you'd like.

from docs.