Talos worker nodes with multipath LUNs

[steven-cascante]

Hello everyone, I’m getting started with Talos and I’m very excited, but I’m having issues mounting a LUN using multipath.

Currently, I have a cluster running Talos version 1.12.5 with 3 control plane nodes and 4 worker nodes.

Each worker node has one 1-TB LUN assigned, accessed through 8 Fibre Channel paths (sda–sdh). The operating system is installed on the nvme0n1 disk.

The following kernel modules were loaded:

kernel:
modules:
- name: nbd
- name: iscsi_tcp
- name: dm_multipath
- name: dm_round-robin
- name: configfs

The multipath configuration was defined as follows:

apiVersion: v1alpha1
kind: ExtensionServiceConfig
name: multipathd
configFiles:
- content: |
defaults {
user_friendly_names yes
find_multipaths yes
path_selector "round-robin 0"
no_path_retry fail
path_grouping_policy multibus
}
mountPath: /etc/multipath.conf

After rebooting the server, the disks and volumes are displayed.

My intention is to create one user volume using this LUN on top of mpatha (dm-0) so that all paths are used. However, when defining the user volume:

apiVersion: v1alpha1
kind: UserVolumeConfig
name: lun1-volume

provisioning:
diskSelector:
match: disk.symlinks.exists(s, s == "/dev/disk/by-id/dm-name-mpatha")
minSize: 1TB

filesystem:
type: xfs

The change is applied without rebooting, but errors appear indicating that /dev/dm-0p1 cannot be found:

user: warning: [2026-03-16T16:14:16.275975203Z]: [talos] volume status {"component": "controller-runtime", "controller": "block.VolumeManagerController", "volume": "u-lun1-volume", "phase": "failed -> failed", "error": "error probing disk: open /dev/dm-0p1: no such file or directory", "location": "/dev/dm-0p1", "parentLocation": "/dev/dm-0"}

When I reboot the worker the LUN is mounted over just 1 path (/dev/sda1), not mpath.

10.1.14.55 runtime VolumeStatus u-lun1-volume 2 partition ready /dev/sda1 1.1 TB

I would like to know what the correct way to mount LUNs with multipath is: whether it should be done using UserVolumeConfig, RawVolumeConfig, or ExistingVolumeConfig, since both UserVolumeConfig and RawVolumeConfig fail when they attempt to create a partition on the dm-0 disk.

[smira]

You can't have a partition over device-mapper devices, so you can only use whole-disk UserVolumeConfig.

[steven-cascante]

Thank you. I configured the device mapper device as you suggested, using the whole disk, and it worked like a charm.