Existing volumes allow mounting pre-existing partitions or disks that are already formatted and contain data. This is useful for migrating data from another system or reusing existing disks without reformatting them. Existing volumes match a partition or a disk using a volume selector expression. Existing volumes are mounted under /var/mnt/<volume-name>, and this location gets automatically propagated into the kubelet container to provide additional features like subPath mounts.
Note: If you need to allocate a volume to be mounted to a container, please see User Volumes guide.

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Declaring Existing Volumes

To declare an existing volume, append the following document to the machine configuration: 
# existing-volume.patch.yaml
apiVersion: v1alpha1
kind: ExistingVolumeConfig
name: my-data-volume
discovery:
    volumeSelector:
        match: volume.partition_label == "MY-DATA"
For example, this machine configuration patch can be applied using the following command: 
talosctl --nodes <NODE> patch mc --patch @raw-volume.patch.yaml
In this example, a existing partition with partition label MY-DATA will be mounted as under /var/mnt/my-data-volume. The status of the volume can be checked using the following command: 
$ talosctl get volumestatus e-my-data-volume # note e- prefix
NODE         NAMESPACE   TYPE           ID                VERSION   TYPE        PHASE   LOCATION    SIZE
172.20.0.5   runtime     VolumeStatus   e-my-data-volume  1         partition   ready   /dev/sda1   2.0 GB
If the volume is no longer needed, it can be removed by deleting the ExistingVolumeConfig document from the machine configuration. Talos will automatically unmount the volume, but it will not try to wipe the underlying data.