配置Multipath多路径环境

环境介绍：

在ISCSI服务基础上修改配置实现Multipath多路径环境

ISCSI服务配置中Server eth0:192.168.4.101 Client eth0:192.168.4.102

Multipath中需要在Server和Client中再添加一块网卡eth1

Server eth1:192.168.2.101 Client eth0:192.168.2.102

1、Server端修改ISCSI的ACL配置，增加192.168.2.102的允许权限

[[email protected] ~]# tail -5 /etc/tgt/targets.conf 
<target iqn.2018-04.com.example.node1:server.target1>
	backing-store /dev/sda1
	initiator-address 192.168.4.102
	initiator-address 192.168.2.102
</target>

2、Client端通过192.169.2.101发现Server共享

[[email protected] ~]# iscsiadm --mode discoverydb --type sendtargets --portal 192.168.2.101 --discover

3、重启ISCSI服务，发现有两条路径连接到Server的共享存储

[[email protected] ~]# /etc/init.d/iscsi restart
停止 iscsi：                                               [确定]
正在启动 iscsi：                                           [确定]
[[email protected] ~]# lsblk 
NAME                        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0                          11:0    1 1024M  0 rom  
vda                         252:0    0   50G  0 disk 
├─vda1                      252:1    0  500M  0 part /boot
└─vda2                      252:2    0 49.5G  0 part 
  ├─VolGroup-lv_root (dm-0) 253:0    0 47.6G  0 lvm  /
  └─VolGroup-lv_swap (dm-1) 253:1    0    2G  0 lvm  [SWAP]
sdb                           8:16   0   20G  0 disk 
└─sdb1                        8:17   0  976M  0 part 
sdc                           8:32   0   20G  0 disk 
└─sdc1                        8:33   0  976M  0 part 

4、安装device-mapper-multipath

[[email protected] ~]# yum -y install device-mapper-multipath

5、关闭为共享存储自动命名的功能，并生成配置文件

[[email protected] ~]# mpathconf --user_friendly_names n
[[email protected] ~]# ls /etc/multipath.conf
/etc/multipath.conf

6、查看已连接的共享设备的wwid，确认设置多路径的两个目标存储设备为同一设备

[[email protected] ~]# /lib/udev/scsi_id --whitelisted --device=/dev/sdb
1IET     00010001
[[email protected] ~]# /lib/udev/scsi_id --whitelisted --device=/dev/sdc
1IET     00010001

7、修改配置文件，启动服务

[[email protected] ~]# sed -n '25,28p;102,107p' /etc/multipath.conf 
defaults {
	user_friendly_names no
	getuid_callout          "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
}
multipaths {
       multipath {
               wwid                    "1IET     00010001"
               alias                   mpa
       }
}
[[email protected] ~]# /etc/init.d/multipathd start;chkconfig multipathd on

[[email protected] ~]# ls /dev/mapper/    ##查看Multipath共享设备的别名
control  mpa  mpap1  VolGroup-lv_root  VolGroup-lv_swap

8、重启ISCSI服务查看磁盘情况

[[email protected] ~]# /etc/init.d/iscsi restar
停止 iscsi：                                               [确定]
正在启动 iscsi：                                           [确定]
[[email protected] ~]# lsblk 
NAME                        MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
sr0                          11:0    1 1024M  0 rom   
vda                         252:0    0   50G  0 disk  
├─vda1                      252:1    0  500M  0 part  /boot
└─vda2                      252:2    0 49.5G  0 part  
  ├─VolGroup-lv_root (dm-0) 253:0    0 47.6G  0 lvm   /
  └─VolGroup-lv_swap (dm-1) 253:1    0    2G  0 lvm   [SWAP]
sdc                           8:32   0   20G  0 disk  
└─mpa (dm-2)                253:2    0   20G  0 mpath 
  └─mpap1 (dm-3)            253:3    0  976M  0 part  /var/lib/mysql
sdb                           8:16   0   20G  0 disk  
└─mpa (dm-2)                253:2    0   20G  0 mpath 
  └─mpap1 (dm-3)            253:3    0  976M  0 part  /var/lib/mysql

9、挂载Multipath共享存储到mysql应用数据目录，也可以把挂载工作写到/etc/fstab实现开机自动挂载

[[email protected] ~]# mount /dev/mapper/mpap1 /var/lib/mysql/