pecan@tux ~ $ sudo dockerd
DEBU[0000] docker group found. gid: 987                 
DEBU[0000] Listener created for HTTP on unix (/var/run/docker.sock) 
INFO[0000] libcontainerd: new containerd process, pid: 3121 
WARN[0000] containerd: low RLIMIT_NOFILE changing to max  current=1024 max=4096
DEBU[0000] containerd: read past events                  count=0
DEBU[0000] containerd: supervisor running                cpus=4 memory=7849 runtime=docker-runc runtimeArgs=[] stateDir=/var/run/docker/libcontainerd/containerd
DEBU[0000] containerd: grpc api on /var/run/docker/libcontainerd/docker-containerd.sock 
DEBU[0000] libcontainerd: containerd health check returned error: rpc error: code = 14 desc = grpc: the connection is unavailable 
DEBU[0001] Using default logging driver json-file       
DEBU[0001] Golang's threads limit set to 56430          
DEBU[0001] backingFs=extfs,  projectQuotaSupported=false 
DEBU[0001] Cleaning up old mountid : start.             
Error starting daemon: error initializing graphdriver: /var/lib/docker contains several valid graphdrivers: overlay, overlay2; Please cleanup or explicitly choose storage driver (-s <DRIVER>)