Cannot mount an external volume

[m-vitale]

I'm trying to mount a lvm volume composed of two nvme drives that have been passed through to the VM running talos.
The disk I'd like to mount is:

talosctl -n 10.0.1.207 get disks -o yaml                                    
Found existing alias for "talosctl". You should use: "t"
node: 10.0.1.207
metadata:
    namespace: runtime
    type: Disks.block.talos.dev
    id: dm-0
    version: 5
    owner: block.DisksController
    phase: running
    created: 2025-06-24T14:51:44Z
    updated: 2025-06-24T14:51:45Z
spec:
    dev_path: /dev/dm-0
    size: 2000406183936
    pretty_size: 2.0 TB
    io_size: 512
    sector_size: 512
    readonly: false
    cdrom: false
    bus_path: /virtual
    sub_system: /sys/class/block
    secondary_disks:
        - nvme0n1
        - nvme1n1
    symlinks:
        - /dev/disk/by-diskseq/17
        - /dev/disk/by-id/dm-name-longhorn_vg-longhorn_lv
        - /dev/disk/by-id/dm-uuid-LVM-HQ4iQD5BUOfvVpRHV1RaWkoN8ZEg3CHjJJIwKV2MAjpYHx2Ihx36T0zy8zJx9X6X
        - /dev/disk/by-uuid/e95a70cb-4c84-4355-bd0b-3de5af0f3e34

One of my attempts is:

machine:
  disks:
    - device: /dev/dm-0
      partitions:
        - mountpoint: /var/mnt/storage

but although this is accepted without errors when the node reboots I'm met with 'no disks matched for volume' and the error message talks about a volume '/dev/dm-0-1' and I'm not sure where the suffix '-1' comes from.

I've read the documentation at https://www.talos.dev/v1.10/talos-guides/configuration/disk-management/ and I cannot make much sense of it. My question on slack resulted in a request for support.zip and I'm attaching it here, although what I'm looking for is an example of a config patch that mounts a physical drive (or a lvm volume but I'd think that would be the same)
support.zip

[smira]

Talos doesn't support this at the moment, what you're looking for is #11153

[m-vitale]

I'm very confused here. I don't particularly mind talos allowing me to import existing volumes, this one was from before I migrated to Talos and I got the impression Talos didn't support creating lvm volumes, but I'd be ok with Talos managing the disk completely, including formatting. Are you saying Talos doesn't support mounting lvm volumes or Talos is not able to mount disks in general (e.g. if I were to mount one of the two nvme disks)?
But then I'm totally puzzled by the entire section on disk management. Which disks can be managed and how?

And I'd think people using longhorn or ceph would routinely need something like this. I haven't found anything on longhorn that works for me (https://kubito.dev/posts/talos-linux-additonal-disks-to-nodes/ for instance; I'll have to try with the physical disks, but I don't see how it can make a difference as all Talos would have to do for this piece is mounting the volume). I'll start looking in ceph-land to see if people have managed to do something that works.

[smira]

Ceph does mounting, partioning and stuff itself, Talos is not involved into it.

Rook/Ceph, Longhorn, etc. work without issues on Talos, and your question is not related.

[m-vitale]

My question related to talos is whether Talos can mount an external physical drive different from the one it install itself onto.
The rather opaque documentation seems to suggest that it is possible to do so, otherwise I don't understand what this is trying to say. Looks to me that is possible to mount an external disk.
Also, how does one get to something like:

$ talosctl get volumestatus u-ceph-data # note u- prefix
NAMESPACE   TYPE           ID            VERSION   TYPE        PHASE   LOCATION         SIZE
runtime     VolumeStatus   u-ceph-data   2         partition   ready   /dev/nvme0n1p2   200 GB

I've no idea how that partition would then be mounted into the kubelet so that it can then be passed as a hostPath to pods, but that would be a next step. For now I'd be happy to be able to mount a physical drive, bonus points if I could mount an lvm volume.

In short, if I have a physical drive /dev/sdb different from the /dev/sda Talos uses for its own installation, is there any configuration patch one can use to make /dev/sdb appear under /var/mnt/storage. The disk could be preformatted or not, at Talos preference.

[smira]

In short, if I have a physical drive /dev/sdb different from the /dev/sda Talos uses for its own installation, is there any configuration patch one can use to make /dev/sdb appear under /var/mnt/storage. The disk could be preformatted or not, at Talos preference.

It is explained the in same document you posted above.