grub_device ignored when args.devices != 0 and args.devices > 1

[Gabriel Samfira]

When deploying a server with more than 1 disk, using whole disk images, the selected boot device from storage configuration is ignored, and curtin writes the disk image to the first block device in the list.

The devpath is correctly identified here:

https://git.launchpad.net/curtin/tree/curtin/commands/block_meta.py#n1950

and it is completely ignored, because len(devices) is > 1, and it selects the first disk from the list of a sorted args.devices here:

https://git.launchpad.net/curtin/tree/curtin/commands/block_meta.py#n1997

[Ryan Harper (raharper)]

Thanks for filing a bug. Can you provide your curtin storage config and command line (if you're invoking it manually)?

[Gabriel Samfira (gabriel-samfira)]

Hi Ryan,

Curtin is invoked by the MAAS userdata:

https://paste.ubuntu.com/p/Nt8J367b7Y/

I have attached the storage config for the node.

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Some more debugging leads:

The following snippet from the installation log:

https://paste.ubuntu.com/p/xC9hFRJjhj/

is generated by:

https://git.launchpad.net/curtin/tree/curtin/commands/block_meta.py#n95

The following snippet from the installation log:

https://paste.ubuntu.com/p/5RRxYwCWWD/

is generated by:

https://git.launchpad.net/curtin/tree/curtin/commands/block_meta.py#n1993

I fixed it in my local MAAS install by applying the following patch:

https://paste.ubuntu.com/p/KBTdCFZDnK/

[Ryan Harper (raharper)]

Thanks for the information.

Since you've provided a potential fix, would you be interested in contributing it directly?

https://curtin.readthedocs.io/en/latest/topics/hacking.html

[Gabriel Samfira (gabriel-samfira)]

Hi Ryan,

Apologies for the late reply.

What I did is a hack at best. I currently have no bandwidth to implement a proper fix and write tests for it.