Help requested: VM w/ luks-btrfs-raid example does not build

[cdata]

Hello, I've been having some stuttering success with using Disko for the first time. I have a setup where I wish to test the configuration in a VM locally. I got a LUKS+Btrfs setup working great. Then, I tried to adapt it based on the LUKS+Btrfs+RAID1 example and ran into a problem.

When I try to build the VM using the RAID example, it fails during disk creation. The full log is attached here. The critical failure point AFAICT is here:

+ mount /dev/mapper/p2 /tmp/tmp.199fvLzrll -o subvol=/
[   36.047665] BTRFS error (device dm-1): devid 2 uuid 25b46a4d-be57-4e52-b025-c1e603233b60 is missing
[   36.048657] BTRFS error (device dm-1): failed to read the system array: -2
[   36.050159] BTRFS error (device dm-1): open_ctree failed: -2
mount: /tmp/tmp.199fvLzrll: fsconfig() failed: No such file or directory.
       dmesg(1) may have more information after failed mount system call.

I have created a minimal reproduction case that demonstrates the issue I'm running up against here: https://github.com/cdata/disko-luks-btrfs-raid-vm-not-working

In the test case, I build the VM using the command nix build .\#test-vm to reproduce the issue.

I tried running the checks in the Disko repo to make sure it wasn't some kind of environmental issue with my local system. The checks all pass, so I assume there is something I'm missing or that I configured incorrectly that is causing this issue.

I'm new to using Disko and would be grateful for any help or advice you can provide. Thanks in advance!

[johanjk]

Disko creates volumes sequentially, and by group. p1 is likely not available yet at the time disko attempts to create the p2 raid.

What will likely work is making p2 a lvm pv and then create the raid as a lvm vg, as that happens after all volumes are created (yes it's hacky and you end up with a unwanted lvm pv)

Otherwise, splitting your disko config into two files is possible, see https://github.com/nix-community/disko/issues/962#issuecomment-2781067044 for an example, although it is error prone.

[johanjk]

This has worked for me in the past (using the lvm pv method)

{
  disko.devices = {
    disk = {
      p1 = {
        type = "disk";
        device = "/dev/nvme0n1";
        content = {
          type = "gpt";
          partitions = {
            luks = {
              label = "disk1";
              size = "100%";
              content = {
                type = "luks";
                name = "main_crypted";
                # ...
                content = {
                  type = "lvm_pv";
                  vg = "pool_main";
                };
              };
            };
          };
        };
      };
      p2 = {
        type = "disk";
        device = "/dev/nvme1n1";
        content = {
          type = "gpt";
          partitions = {
            luks = {
              label = "disk2";
              size = "100%";
              content = {
                type = "luks";
                name = "main2_crypted";
                # ...
              };
            };
          };
        };
      };
    };

    lvm_vg = {
      pool_main = {
        type = "lvm_vg";
        lvs = {
          main = {
            size = "100%";
            content = {
              type = "btrfs";
              extraArgs = [
                "-d raid1"
                "/dev/mapper/main2_crypted"
              ];
              subvolumes = {
                # ...
              };
            };
          };
        };
      };
    };
  };
}

[cdata]

Thanks for the advice @johanjk I'll give it a shot.

The thing that got me thinking that I'm just doing something wrong is that I copied the example verbatim, and the check which tests the example passes. This suggests to me (though I am naive) that I should be able to make the example work for me without significant modification.

[cdata]

Friendly bump on this. I'm interested to know if perhaps there is something about the setup in the checks that I can adopt to make this work for me locally. Any pointers would be appreciated.