#### ceph软件包升级完成，执行命令重启服务

sudo systemctl restart ceph-mds@"$HOSTNAME"

#### 故障现象

服务可以启动，启动后显示有报错信息：

Nov 23 17:14:45 ceph-6-12 systemd[1]:        [/usr/lib/systemd/system/ceph-mds@.service:18] Unknown lvalue ‘TasksMax‘ in section ‘Service‘

详细如下：

[ptmind@ceph-6-12 ~]$ sudo systemctl status ceph-mds@"$HOSTNAME"

```

● ceph-mds@ceph-6-12.service - Ceph metadata server daemon

   Loaded: loaded (/usr/lib/systemd/system/ceph-mds@.service; enabled; vendor preset: disabled)

   Active: active (running) since Wed 2016-11-23 17:14:45 CST; 57s ago

 Main PID: 538956 (ceph-mds)

   CGroup: /system.slice/system-ceph\x2dmds.slice/ceph-mds@ceph-6-12.service

           └─538956 /usr/bin/ceph-mds -f --cluster ceph --id ceph-6-12 --setuser ceph --setgroup ceph

Nov 23 17:14:45 ceph-6-12 systemd[1]: Started Ceph metadata server daemon.

Nov 23 17:14:45 ceph-6-12 systemd[1]: Starting Ceph metadata server daemon...

Nov 23 17:14:45 ceph-6-12 ceph-mds[538956]: starting mds.ceph-6-12 at :/0

Nov 23 17:14:45 ceph-6-12 systemd[1]: [/usr/lib/systemd/system/ceph-mds@.service:18] Unknown lvalue ‘TasksMax‘ in section ‘Service‘

Nov 23 17:14:45 ceph-6-12 systemd[1]: [/usr/lib/systemd/system/ceph-mds@.service:18] Unknown lvalue ‘TasksMax‘ in section ‘Service‘

Nov 23 17:14:45 ceph-6-12 systemd[1]: [/usr/lib/systemd/system/ceph-mds@.service:18] Unknown lvalue ‘TasksMax‘ in section ‘Service‘

Nov 23 17:14:46 ceph-6-12 systemd[1]: [/usr/lib/systemd/system/ceph-mds@.service:18] Unknown lvalue ‘TasksMax‘ in section ‘Service‘

Nov 23 17:14:46 ceph-6-12 systemd[1]: [/usr/lib/systemd/system/ceph-mds@.service:18] Unknown lvalue ‘TasksMax‘ in section ‘Service‘

Nov 23 17:14:53 ceph-6-12 systemd[1]: Started Ceph metadata server daemon.

```

#### 查询相关文档：

http://tracker.ceph.com/issues/15560        

http://tracker.ceph.com/issues/15581

文档都说是个bug ，又碰到一个bug ，汗。。。。。。。。。。

根据文档提示信息排查解决，发现这个问题只要安装或升级systemd基础库相关软件包，就能解决，所以果断安装升级systemd。

sudo yum install systemd-*

#### 然后重启服务：

sudo systemctl restart ceph-mds@"$HOSTNAME"

再查查看服务状态：      

[ptmind@ceph-6-12 ~]$ sudo systemctl status ceph-mds@"$HOSTNAME"        

```

● ceph-mds@ceph-6-12.service - Ceph metadata server daemon

   Loaded: loaded (/usr/lib/systemd/system/ceph-mds@.service; enabled; vendor preset: disabled)

   Active: active (running) since Wed 2016-11-23 17:59:51 CST; 8s ago

 Main PID: 666298 (ceph-mds)

   CGroup: /system.slice/system-ceph\x2dmds.slice/ceph-mds@ceph-6-12.service

           └─666298 /usr/bin/ceph-mds -f --cluster ceph --id ceph-6-12 --setuser ceph --setgroup ceph

Nov 23 17:59:51 ceph-6-12 systemd[1]: Started Ceph metadata server daemon.

Nov 23 17:59:51 ceph-6-12 systemd[1]: Starting Ceph metadata server daemon...

Nov 23 17:59:51 ceph-6-12 ceph-mds[666298]: starting mds.ceph-6-12 at :/0

```

报错信息不再提示；

本文出自 “康建华” 博客，谢绝转载！

ceph升级到10.2.3 版本启动服务报错：Unknown lvalue 'TasksMax' in section 'Service'