求教：cinder 重启后，虚拟机无法启动，iscsi盘丢失，iscsi认证失败，是什么问题？

1、OS信息：CentOS Linux release 7.2.1511 (Core)
2、openstack 版本：Liberty
3、cinder后端对接lvm

一、操作
虚拟机挂载由cinder创建的卷，并通过iscsi挂载

重启虚拟机节点后，/dev/disk/by-path路径下，对应由iscsi连接产生的盘符丢失

二、查询
service iscsid status
Redirecting to /bin/systemctl status  iscsid.service
● iscsid.service - Open-iSCSI
Loaded: loaded (/usr/lib/systemd/system/iscsid.service; enabled; vendor preset: disabled)
Active: active (running) since Thu 2016-03-31 17:35:11 CST; 13min ago
   Docs: man:iscsid(8)
         man:iscsiadm(8)
  Process: 2293 ExecStart=/usr/sbin/iscsid (code=exited, status=0/SUCCESS)
Main PID: 2296 (iscsid)
CGroup: /system.slice/iscsid.service
         ├─2295 /usr/sbin/iscsid
         └─2296 /usr/sbin/iscsid

Mar 31 17:35:10 compute-192-168-6-56 systemd[1]: Starting Open-iSCSI...
Mar 31 17:35:11 compute-192-168-6-56 iscsid[2293]: iSCSI logger with pid=2295 started!
Mar 31 17:35:11 compute-192-168-6-56 systemd[1]: Started Open-iSCSI.
Mar 31 17:35:12 compute-192-168-6-56 iscsid[2295]: iSCSI daemon with pid=2296 started!
Mar 31 17:35:12 compute-192-168-6-56 iscsid[2295]: connect to 192.168.6.56:3260 failed (Connection refused)
Mar 31 17:35:15 compute-192-168-6-56 iscsid[2295]: connect to 192.168.6.56:3260 failed (Connection refused)
Mar 31 17:35:19 compute-192-168-6-56 iscsid[2295]: connect to 192.168.6.56:3260 failed (Connection refused)
Mar 31 17:35:23 compute-192-168-6-56 iscsid[2295]: connect to 192.168.6.56:3260 failed (Connection refused)
Mar 31 17:35:27 compute-192-168-6-56 iscsid[2295]: conn 0 login rejected: initiator failed authorization with target
Mar 31 17:35:27 compute-192-168-6-56 iscsid[2295]: Connection1:0 to [target: iqn.2010-10.org.openstack:volume-637dd17b-8c64-44c7-a8ee-2cb1b123aacf, portal: 192.168.6.56,3260] th...is shutdown.
Hint: Some lines were ellipsized, use -l to show in full.

三、node_acls 认证信息丢失
/etc/target/saveconfig.json文件中的node_acls的认证（用户，密码）信息都丢失了。

四、同时保存在该路径下的用户密码信息也都丢失了

/sys/kernel/config/target/iscsi/iqn.2010-10.org.openstack:volume-889fca09-f0f5-42ed-826f-51261418e9ad/tpgt_1/acls/iqn.1994-05.com.redhat:4a683be0abb2/auth

五、求教
该问题是哪些配置有问题，或者版本上存在差异，导致不兼容，还是其余问题。
麻烦知道的告知下，小弟不胜感谢！