我尝试在Ceph Nautilus 14.2.19上的Centos 7上手动创建ceph-mds。首先，我在/var/lib/ceph/mds内以<clusterid>-mds.<hostid>的格式创建了一个文件夹，然后运行以下命令：

ceph-authtool --create-keyring /var/lib/ceph/mds/ceph-mds.<hostid>/keyring --gen-key -n mds.<hostid>
ceph auth add mds.<hostid> osd "allow rwx" mds "allow *" mon "allow profile mds" -i /var/lib/ceph/mds/ceph-mds.<hostid>/keyring

然后我将/var/lib/ceph/mds/的内容的用户权限更改为ceph:ceph。当我检查keyring和添加到ceph auth list上的keyring是否匹配mds时，我可以确认它们是匹配的。但是，当我运行systemctl start ceph-mds@mds时，守护进程没有启动，并且在journalctl上，我得到以下错误输出：

Apr 20 11:38:14 <hostid> ceph-mds[44742]: 2021-04-20 11:38:14.592 7f53bcaef700 -1 monclient(hunting): handle_auth_bad_method server allowed_methods [2] but i only support [2]
Apr 20 11:38:14 <hostid> ceph-mds[44742]: failed to fetch mon config (--no-mon-config to skip).

systemctl status ceph-mds@mds.的完整输出：

● ceph-mds@mds.<hostid>.service - Ceph metadata server daemon
   Loaded: loaded (/usr/lib/systemd/system/ceph-mds@.service; disabled; vendor preset: disabled)
   Active: failed (Result: start-limit) since Tue 2021-04-20 12:28:15 +03; 11min ago
  Process: 15564 ExecStart=/usr/bin/ceph-mds -f --cluster ${CLUSTER} --id %i --setuser ceph --setgroup ceph (code=exited, status=1/FAILURE)
 Main PID: 15564 (code=exited, status=1/FAILURE)

Apr 20 12:28:15 <hostid> systemd[1]: Unit ceph-mds@mds.<hostid>.service entered failed state.
Apr 20 12:28:15 <hostid> systemd[1]: ceph-mds@mds.<hostid>.service failed.
Apr 20 12:28:15 <hostid> systemd[1]: ceph-mds@mds.<hostid>.service holdoff time over, scheduling restart.
Apr 20 12:28:15 <hostid> systemd[1]: Stopped Ceph metadata server daemon.
Apr 20 12:28:15 <hostid> systemd[1]: start request repeated too quickly for ceph-mds@mds.<hostid>.service
Apr 20 12:28:15 <hostid> systemd[1]: Failed to start Ceph metadata server daemon.
Apr 20 12:28:15 <hostid> systemd[1]: Unit ceph-mds@mds.<hostid>.service entered failed state.
Apr 20 12:28:15 <hostid> systemd[1]: ceph-mds@mds.<hostid>.service failed.

这可能是什么原因？