Dependency Installed:
device-mapper-multipath-libs.x86_64 0:0.4.9-72.el6
Complete!
如果不方便配置yum，也可以直接rpm安装这两个包：
[root@jyrac2 Packages]# rpm -ivh device-mapper-multipath-libs-0.4.9-72.el6.x86_64.rpm
warning: device-mapper-multipath-libs-0.4.9-72.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID fd431d51: NOKEY
Preparing... ########################################### [100%]
1:device-mapper-multipath########################################### [100%]
[root@jyrac2 Packages]# rpm -ivh device-mapper-multipath-0.4.9-72.el6.x86_64.rpm
warning: device-mapper-multipath-0.4.9-72.el6.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID fd431d51: NOKEY
Preparing... ########################################### [100%]
1:device-mapper-multipath########################################### [100%]
2.设置服务开机启动
查询当前开机自启用设置：
chkconfig --list|grep multipathd
确认内核成功加载：
modprobe -l |grep multipath
确认开启开机自启动：
[root@jyrac1 ~]# chkconfig multipathd on
[root@jyrac1 ~]# chkconfig --list|grep multipathd
multipathd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
3.生成multipath配置文件
生成multipath配置文件:
/sbin/mpathconf --enable
确认服务状态：
service multipathd status
4.multipath的常用命令
常用命令：
--生成multipath配置文件
/sbin/mpathconf --enable
--显示多路径的布局
multipath -ll
--重新刷取
multipath -v2
--清空所有多路径
multipath -F
针对上述常用命令，实际操作的记录，供参考：
[root@jyrac1 ~]# multipath -ll
Jul 18 15:57:18 | DM multipath kernel driver not loaded
Jul 18 15:57:18 | /etc/multipath.conf does not exist, blacklisting all devices.
Jul 18 15:57:18 | A sample multipath.conf file is located at
Jul 18 15:57:18 | /usr/share/doc/device-mapper-multipath-0.4.9/multipath.conf
Jul 18 15:57:18 | You can run /sbin/mpathconf to create or modify /etc/multipath.conf
Jul 18 15:57:18 | DM multipath kernel driver not loaded
[root@jyrac1 ~]# chkconfig --list|grep multipathd
multipathd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
[root@jyrac1 ~]# modprobe -l |grep multipath
kernel/drivers/md/dm-multipath.ko
[root@jyrac1 ~]# service multipathd status
multipathd is stopped
[root@jyrac1 ~]# service multipathd start
Starting multipathd daemon: [ OK ]
[root@jyrac1 ~]# multipath -ll
Jul 18 15:59:00 | /etc/multipath.conf does not exist, blacklisting all devices.
Jul 18 15:59:00 | A sample multipath.conf file is located at
Jul 18 15:59:00 | /usr/share/doc/device-mapper-multipath-0.4.9/multipath.conf
Jul 18 15:59:00 | You can run /sbin/mpathconf to create or modify /etc/multipath.conf
[root@jyrac1 ~]# /sbin/mpathconf --enable
[root@jyrac1 ~]# multipath -v2
Jul 18 16:02:52 | mpatha: ignoring map
Jul 18 16:02:52 | mpathb: ignoring map
Jul 18 16:02:52 | mpathc: ignoring map
Jul 18 16:02:52 | mpathd: ignoring map
Jul 18 16:02:52 | mpathe: ignoring map
Jul 18 16:02:52 | mpathf: ignoring map
create: mpathg (1IET 00010001) undef IET,VIRTUAL-DISK
size=10G features='0' hwhandler='0' wp=undef
|-+- policy='round-robin 0' prio=1 status=undef
| `- 10:0:0:1 sdi 8:128 undef ready running
`-+- policy='round-robin 0' prio=1 status=undef
`- 11:0:0:1 sdj 8:144 undef ready running
[root@jyrac1 ~]# multipath -ll
mpathg (1IET 00010001) dm-2 IET,VIRTUAL-DISK
size=10G features='0' hwhandler='0' wp=rw
|-+- policy='round-robin 0' prio=1 status=active
| `- 10:0:0:1 sdi 8:128 active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
`- 11:0:0:1 sdj 8:144 active ready running
[root@jyrac1 ~]#
这里测试没有问题后，为了后续方便测试ASM磁盘组，在iSCSI服务端又分了一个10g的lv，模拟存储端分出的一个LUN，最后在这边就应该有两个多路径聚合盘了。同样的方法在RAC的另一个节点也都配置好。
5.udev绑定权限
我这里系统是RHEL6.5，对于multipath的权限，手工去修改几秒后会变回root。所以需要使用udev去绑定好权限。
搜索对应的配置文件模板：
[root@jyrac1 ~]# find / -name 12-*
/usr/share/doc/device-mapper-1.02.79/12-dm-permissions.rules