All error codes

disk_is_system

HTTP 422 This is the system disk

What happened

The disk you addressed is the server's system disk. It is created and removed together with the server, and its size belongs to the server's own disk_gb field, so it is not managed as a separate disk resource.

What to do

To resize it, send disk_gb on the server itself; to remove it, delete the server. Data disks are the ones listed with is_system false.

Retrying

Fix the request and send it again.

How it arrives

{
    "type": "https://docs.fiberax.com/errors/disk_is_system",
    "title": "This is the system disk",
    "status": 422,
    "code": "disk_is_system",
    "request_id": "a277dcd1ca652c65"
}

Branch your code on code, never on the wording of title.