I can't start etcd service now, and it always said "etcd.service start request repeated too quickly, refusing to start". No sure whether the etcd service runs well or not. How to solve it?
[root@localhost ~]# etcd -version
etcd Version: 2.0.13
Git SHA: 92e3895
Go Version: go1.4.2
Go OS/Arch: linux/amd64
[root@localhost ~]# etcdctl -version
etcdctl version 2.0.13
[root@localhost ~]# systemctl restart etcd
[root@localhost ~]# systemctl status etcd
etcd.service - Etcd Server
Loaded: loaded (/etc/systemd/system/etcd.service; enabled)
Active: failed (Result: start-limit) since Wed 2015-08-19 09:35:17 EDT; 1h 1min ago
Process: 5403 ExecStart=/bin/bash -c GOMAXPROCS=$(nproc) /usr/bin/etcd (code=exited, status=1/FAILURE)
Main PID: 5403 (code=exited, status=1/FAILURE)
CGroup: /system.slice/etcd.service
Aug 19 09:35:17 localhost.localdomain systemd[1]: etcd.service: main process exited, code=exited, status=1/FAILURE
Aug 19 09:35:17 localhost.localdomain systemd[1]: Unit etcd.service entered failed state.
Aug 19 09:35:17 localhost.localdomain systemd[1]: etcd.service holdoff time over, scheduling restart.
Aug 19 09:35:17 localhost.localdomain systemd[1]: Stopping Etcd Server...
Aug 19 09:35:17 localhost.localdomain systemd[1]: Starting Etcd Server...
Aug 19 09:35:17 localhost.localdomain systemd[1]: etcd.service start request repeated too quickly, refusing to start.
Aug 19 09:35:17 localhost.localdomain systemd[1]: Failed to start Etcd Server.
Aug 19 09:35:17 localhost.localdomain systemd[1]: Unit etcd.service entered failed state.
[root@localhost ~]# journalctl -u etcd
Aug 19 09:35:17 localhost.localdomain systemd[1]: Stopping Etcd Server...
Aug 19 09:35:17 localhost.localdomain systemd[1]: Starting Etcd Server...
Aug 19 09:35:17 localhost.localdomain systemd[1]: Started Etcd Server.
Aug 19 09:35:17 localhost.localdomain bash[5403]: 2015/08/19 09:35:17 etcd: ETCD_LISTEN_CLIENT_URLS set but ETCD_ADVERTISE_CLIENT_URLS not, setting ETCD_ADVERTISE_CLIENT_URLS to ETCD_ADVERTISE_CLIENT_URLS
Aug 19 09:35:17 localhost.localdomain bash[5403]: 2015/08/19 09:35:17 etcd: error listing data dir: /var/lib/etcd/default.etcd
Aug 19 09:35:17 localhost.localdomain systemd[1]: etcd.service: main process exited, code=exited, status=1/FAILURE
Aug 19 09:35:17 localhost.localdomain systemd[1]: Unit etcd.service entered failed state.
Aug 19 09:35:17 localhost.localdomain systemd[1]: etcd.service holdoff time over, scheduling restart.
Aug 19 09:35:17 localhost.localdomain systemd[1]: Stopping Etcd Server...
Aug 19 09:35:17 localhost.localdomain systemd[1]: Starting Etcd Server...
Aug 19 09:35:17 localhost.localdomain systemd[1]: etcd.service start request repeated too quickly, refusing to start.
Aug 19 09:35:17 localhost.localdomain systemd[1]: Failed to start Etcd Server.
Aug 19 09:35:17 localhost.localdomain systemd[1]: Unit etcd.service entered failed state.