1、报错一

[root@ct ceph]# ceph -s
  cluster:
    id:     dfb110f9-e0e0-4544-9f13-9141750ee9f6
    health: HEALTH_WARN
            Degraded data redundancy: 192 pgs undersized

  services:
    mon: 3 daemons, quorum ct,c1,c2
    mgr: ct(active), standbys: c2, c1
    osd: 2 osds: 2 up, 2 in

  data:
    pools:   3 pools, 192 pgs
    objects: 0  objects, 0 B
    usage:   2.0 GiB used, 2.0 TiB / 2.0 TiB avail
    pgs:     102 active+undersized
             90  stale+active+undersized
查看obs状态，c2没有连接上
[root@ct ceph]# ceph osd status
+----+------+-------+-------+--------+---------+--------+---------+-----------+
| id | host |  used | avail | wr ops | wr data | rd ops | rd data |   state   |
+----+------+-------+-------+--------+---------+--------+---------+-----------+
| 0  |  ct  | 1026M | 1022G |    0   |     0   |    0   |     0   | exists,up |
| 1  |  c1  | 1026M | 1022G |    0   |     0   |    0   |     0   | exists,up |
+----+------+-------+-------+--------+---------+--------+---------+-----------+

解决方法：
在c2重启osd即可解决
[root@c2 ~]# systemctl restart ceph-osd.target

2、报错二

[root@ct ceph]# ceph -s
  cluster:
    id:     44d72edb-4085-4cfc-8652-eb670472f169
    health: HEALTH_WARN
            clock skew detected on mon.c1, mon.c2

  services:
    mon: 3 daemons, quorum ct,c1,c2
    mgr: c1(active), standbys: c2, ct
    osd: 3 osds: 1 up, 1 in

  data:
    pools:   0 pools, 0 pgs
    objects: 0  objects, 0 B
    usage:   1.0 GiB used, 1023 GiB / 1024 GiB avail
    pgs: 

解决方法：
（1）控制节点重启NTP服务
[root@ct ceph]# systemctl restart ntpd
（2）计算节点重新同步控制节点时间
[root@c2 ~]# ntpdate 192.168.100.10
（3）在控制节点重启mon服务
[root@ct ceph]# systemctl restart ceph-mon.target