1. 判断系统是否按照multipath

     rpm -qa|grep device-mapper-multipath

2. 重新加载新增的HBA存储（如果不是HBA存储，不用做这一步）

modprobe -r lpfcmodprobe lpfc

3. 安装multipath

   yum install device-mapper-multipath

4. 检查multipath是否正确加载，如果没有加载，运行下面命令，或者重启操作系统

lsmod|grep multipath[root@Linux01 ~]# lsmod|grep multdm_multipath           17649  1 dm_round_robindm_mod                 81692  12 dm_multipath,dm_mirror,dm_log#重新加载驱动[root@Linux01 ~]# modprobe dm-multipath[root@Linux01 ~]# modprobe dm-round-robin

5. 设置multipath服务自动启动并启动multipath服务

 chkconfig multipathd on service multipathd start

6. multipath基本操作命令

   service multipath start  #启动multipath   multipath -F                  #删除无效路径   multipath -v2                #检查路径，合并路径，格式化路径   multipath -ll                  #检查路径状态

7. 配置/etc/multipath.conf,添加下面内容

blacklist{devnode "^sda"}defaults {user_friendly_names yesudev_dir /devpath_grouping_policy multibusfailback immediateno_path_retry fail}

8. 通过scsi_id 命令获取磁盘的wwid

    这里有几点需要注意一下

    1， 首先，通过scsi_id获取wwid的设备名称，必须可以通过fdisk -l命令可以查到的设备

    2.   注意不要使用网上说的那种 /sbin/scsi_id -s -g /block/sdb 这样，查不出来wwid的，改为 /dev/sdb这样就可以了

    3. 关于scsi_id 命令，Linux有个bug，参考 scsi_id does not return WWID for /dev/sda with aacraid driver

[root@Linux01 ~]# /sbin/scsi_id -u -g /dev/mapper/mpatha14f504e46494c45526d56564a4b6f2d6a4e66552d77434947[root@Linux01 ~]# /sbin/scsi_id -u -g /dev/mapper/mpathb14f504e46494c4552516a6d535a652d637576712d6f726250[root@Linux01 ~]# /sbin/scsi_id -u -g /dev/mapper/mpathc14f504e46494c45527a4e387762672d715632712d68396951[root@Linux01 ~]# /sbin/scsi_id -u -g /dev/mapper/mpathd14f504e46494c45526a4c5a6b58632d395a56312d42527652[root@Linux01 ~]# /sbin/scsi_id -u -g /dev/mapper/mpathe14f504e46494c45526c36694345372d524761642d32736c77

9， 修改multipath.conf配置文件，实现设备的持久化

添加下面内容到配置文件：

multipaths {        multipath {                      wwid                    14f504e46494c45526d56564a4b6f2d6a4e66552d77434947                      alias                   rac-disk-01                      path_grouping_policy    multibus                      path_checker            readsector0                      path_selector           "round-robin 0"                      failback                manual                      rr_weight               priorities                      no_path_retry           5                  }        multipath {                      wwid                    14f504e46494c4552516a6d535a652d637576712d6f726250                      alias                   rac-disk-02                      path_grouping_policy    multibus                      path_checker            readsector0                      path_selector           "round-robin 0"                      failback                manual                      rr_weight               priorities                      no_path_retry           5                  }        multipath {                      wwid                    14f504e46494c45527a4e387762672d715632712d68396951                      alias                   asm-disk-01                      path_grouping_policy    multibus                      path_checker            readsector0                      path_selector           "round-robin 0"                      failback                manual                      rr_weight               priorities                      no_path_retry           5                  }        multipath {                      wwid                    14f504e46494c45526a4c5a6b58632d395a56312d42527652                      alias                   asm-disk-02                      path_grouping_policy    multibus                      path_checker            readsector0                      path_selector           "round-robin 0"                      failback                manual                      rr_weight               priorities                      no_path_retry           5                  }        multipath {                      wwid                    14f504e46494c45526c36694345372d524761642d32736c77                      alias                   asm-disk-03                      path_grouping_policy    multibus                      path_checker            readsector0                      path_selector           "round-robin 0"                      failback                manual                      rr_weight               priorities                      no_path_retry           5                  }         }

10。 重启multipath服务