一个关于ISCSI故障的例子

/var/log/messages的错误描述

Sep 14 04:02:58   kernel:  connection4:0: detected conn error (1011)

Sep 14 04:02:59   iscsid: Kernel reported iSCSI connection 4:0 error (1011) state (3)

Sep 14 04:03:01   kernel:  connection3:0: detected conn error (1011)

Sep 14 04:03:02   iscsid: Kernel reported iSCSI connection 3:0 error (1011) state (3)

Sep 14 04:03:02   kernel:  connection1:0: detected conn error (1011)

Sep 14 04:03:02   kernel:  connection8:0: detected conn error (1011)

Sep 14 04:03:02   kernel:  connection2:0: detected conn error (1011)

Sep 14 04:03:02   kernel:  connection5:0: detected conn error (1011)

Sep 14 04:03:03   iscsid: Kernel reported iSCSI connection 1:0 error (1011) state (3)

Sep 14 04:03:03   iscsid: Kernel reported iSCSI connection 8:0 error (1011) state (3)

Sep 14 04:03:03   iscsid: Kernel reported iSCSI connection 2:0 error (1011) state (3)

Sep 14 04:03:03   iscsid: Kernel reported iSCSI connection 5:0 error (1011) state (3)

Sep 14 04:03:04   iscsid: connection4:0 is operational after recovery (1 attempts)

Sep 14 04:03:08   iscsid: connection3:0 is operational after recovery (1 attempts)

Sep 14 04:03:08   iscsid: connection8:0 is operational after recovery (1 attempts)

Sep 14 04:03:08   iscsid: connection2:0 is operational after recovery (1 attempts)

Sep 14 04:03:08   iscsid: connection1:0 is operational after recovery (1 attempts)

Sep 14 04:03:08   iscsid: connection5:0 is operational after recovery (1 attempts)

解决方法：

用lsscsi命令查看错误的connection对应的disk （/dev/sdX）

[0:0:0:0]    cd/dvd  Optiarc  DVD-ROM DDU820S  MH52  /dev/scd0

[2:0:0:0]    disk    LEFTHAND iSCSIDisk        9500  /dev/sdj

[3:0:0:0]    disk    LEFTHAND iSCSIDisk        9500  /dev/sdk

再去iscsi存储查看每个volume的iscsi session

发现有问题的volume对应的iscsi session有两个或者在两个中间切换，说明有多于一个session尝试登入。

幸运的是，另一个session只是login，没有挂载，不然就有可能破坏这个disk。

找到另外那个session对应的服务器，登出iscsi，问题解决。