In correlation with the end of life (EOL) for MKE 3.5.x, maintenance of this documentation set was discontinued as of 2023-NOV-22. Click here for the latest MKE 3.x version documentation.

Volumes

MKE uses named volumes to persist data on all nodes on which it runs.

Volumes used by MKE manager nodes

Volume name	Contents
ucp-auth-api-certs	Certificate and keys for the authentication and authorization service.
ucp-auth-store-certs	Certificate and keys for the authentication and authorization store.
ucp-auth-store-data	Data of the authentication and authorization store, replicated across managers.
ucp-auth-worker-certs	Certificate and keys for authentication worker.
ucp-auth-worker-data	Data of the authentication worker.
ucp-client-root-ca	Root key material for the MKE root CA that issues client certificates.
ucp-cluster-root-ca	Root key material for the MKE root CA that issues certificates for swarm members.
ucp-controller-client-certs	Certificate and keys that the MKE web server uses to communicate with other MKE components.
ucp-controller-server-certs	Certificate and keys for the MKE web server running in the node.
ucp-kv	MKE configuration data, replicated across managers.
ucp-kv-certs	Certificates and keys for the key-value store.
ucp-metrics-data	Monitoring data that MKE gathers.
ucp-metrics-inventory	Configuration file that the ucp-metrics service uses.
ucp-node-certs	Certificate and keys for node communication.
ucp-backup	Backup artifacts that are created while processing a backup. The artifacts persist on the volume for the duration of the backup and are cleaned up when the backup completes, though the volume itself remains.
mke-containers	Symlinks to MKE component log files, created by ucp-agent.
ucp-kube-apiserver-audit	Audit logs streamed by kube-apiserver container.

Volumes used by MKE worker nodes

Volume name	Contents
ucp-node-certs	Certificate and keys for node communication.
mke-containers	Symlinks to MKE component log files, created by ucp-agent.

You can customize the volume driver for the volumes by creating the volumes prior to installing MKE. During installation, MKE determines which volumes do not yet exist on the node and creates those volumes using the default volume driver.

By default, MKE stores the data for these volumes at /var/lib/docker/volumes/<volume-name>/_data.