下列步骤需要用到ceph命令，需要用到ceph.conf和ceph.client.admin.keyring,提前拷贝到执行命令的机器上

1. 创建mds文件夹

   [root@ceph-0 /etc/ceph]# mkdir -p /var/lib/ceph/mds/ceph-ceph-0

2. 创建keyring

   [root@ceph-0 /etc/ceph]# ceph-authtool --create-keyring /var/lib/ceph/mds/ceph-ceph-0/keyring --gen-key -n mds.ceph-0
   creating /var/lib/ceph/mds/ceph-ceph-0/keyring

3. 导入keyring并且设置权限

   [root@ceph-0 /etc/ceph]# ceph auth add mds.ceph-0 osd "allow rwx" mds "allow *" mon "allow profile mds" -i /var/lib/ceph/mds/ceph-ceph-0/keyring
   added key for mds.ceph-0

4. 修改配置文件

   [root@ceph-0 /etc/ceph]# cat /etc/ceph/ceph.conf
   [global]
   fsid = 8a212a0e-0fb5-4f4a-a1ee-53d7b3783a64
   mon_initial_members = ceph-0
   mon_host = 10.0.0.80
   public_network = 10.0.0.0/24
   auth_cluster_required = cephx
   auth_service_required = cephx
   auth_client_required = cephx
   osd_pool_default_size = 3
   osd_pool_default_min_size = 2
   osd_pool_default_pg_num = 333
   osd_crush_chooseleaf_type = 1
   
   [mds.ceph-0]
   host = ceph-0

5. 启动mds

   [root@ceph-0 /etc/ceph]# ceph-mds --cluster ceph -i ceph-0 -m 10.0.0.80:6789
   starting mds.ceph-0 at

6. 查看是否启动成功

   [root@ceph-0 /etc/ceph]# ceph mds stat
    1 up:standby