今天遇到一次了multipath绑定的问题，所以把multipath简单整理下
1、mutipath

mutipath里Linux下提供的多路径软件，在redhat 5 和 red hat 6 上使用有些区别

2、安装

    安装多路径软件
    yum install kpartx  -y 
    yum install device-mapper-multipath -y
    配置开机启动
    chkconfig multipathd on
    service multipathd start
    service multipathd reload
    创建配置文件
    touch /etc/multipath.conf

3、常用命令

1. multipath -F –删除所有不使用的多路经设备。




2. multipath -v2 –检测所有的路径、多路径和设备映射




3. multipath -l –选项来显示现有多路径配置




4. dmsetup ls –查看设备




5. 交互式查看




# multipathd -k multipathd> show status path checker states: up 7 multipathd> show config --查看配置 multipathd> show devices --显示设备 available block devices: sda devnode whitelisted, monitored sdb devnode whitelisted, monitored sdc devnode whitelisted, monitored sdd devnode whitelisted, monitored sde devnode whitelisted, monitored sdf devnode whitelisted, monitored sdg devnode whitelisted, monitored sr0 devnode blacklisted, unmonitored dm-0 devnode blacklisted, unmonitored dm-1 devnode blacklisted, unmonitored dm-2 devnode blacklisted, unmonitored dm-3 devnode blacklisted, unmonitored dm-4 devnode blacklisted, unmonitored dm-9 devnode blacklisted, unmonitored ram0 devnode blacklisted, unmonitored ram1 devnode blacklisted, unmonitored ram2 devnode blacklisted, unmonitored ram3 devnode blacklisted, unmonitored ram4 devnode blacklisted, unmonitored ram5 devnode blacklisted, unmonitored ram6 devnode blacklisted, unmonitored ram7 devnode blacklisted, unmonitored ram8 devnode blacklisted, unmonitored ram9 devnode blacklisted, unmonitored dm-10 devnode blacklisted, unmonitored loop0 devnode blacklisted, unmonitored loop1 devnode blacklisted, unmonitored loop2 devnode blacklisted, unmonitored loop3 devnode blacklisted, unmonitored loop4 devnode blacklisted, unmonitored loop5 devnode blacklisted, unmonitored loop6 devnode blacklisted, unmonitored loop7 devnode blacklisted, unmonitored ram10 devnode blacklisted, unmonitored ram11 devnode blacklisted, unmonitored ram12 devnode blacklisted, unmonitored ram13 devnode blacklisted, unmonitored ram14 devnode blacklisted, unmonitored ram15 devnode blacklisted, unmonitored zram0 multipathd> show paths --显示路径 hcil dev dev_t pri dm_st chk_st dev_st next_check 0:2:0:0 sda 8:0 1 undef ready running orphan 3:0:0:0 sdb 8:16 1 active ready running XXXXX..... 11/20 3:0:0:1 sdc 8:32 1 active ready running XXXXXXXX.. 16/20 3:0:0:2 sdd 8:48 1 active ready running XXXXXXXX.. 17/20 4:0:0:0 sde 8:64 1 active ready running XXXXXXXXXX 20/20 4:0:0:1 sdf 8:80 1 active ready running XXXX...... 8/20 4:0:0:2 sdg 8:96 1 active ready running XXXXXXX... 14/20 multipathd> show maps --显示映射 name sysfs uuid ocr dm-4 360022a11000a187faf44b43900000013 mpathc dm-3 360022a11000a187f21673b7000000040 mpathb dm-2 360022a11000a187f21673bce00000041 multipathd> show multipaths status --查看状态 name failback queueing paths dm-st write_prot ocr - - 2 active rw mpathc - - 2 active rw mpathb - - 2 active rw multipathd> show multipaths stats --查看状态 name path_faults switch_grp map_loads total_q_time q_timeouts ocr 0 0 1 0 0 mpathc 0 0 0 0 0 mpathb 0 0 0 0 0   multipathd> show topology mpathb (360022a11000a187f21673c8700000043) dm-2 HUASY,S6800T size=300G features='0' hwhandler='0' wp=rw |-+- policy='round-robin 0' prio=1 status=active | `- 3:0:0:0 sdb 8:16 active ready running `-+- policy='round-robin 0' prio=1 status=enabled `- 4:0:0:0 sde 8:64 active ready running mpathc (360022a11000a187f21673c2700000042) dm-3 HUASY,S6800T size=300G features='0' hwhandler='0' wp=rw |-+- policy='round-robin 0' prio=1 status=active | `- 3:0:0:1 sdc 8:32 active ready running `-+- policy='round-robin 0' prio=1 status=enabled `- 4:0:0:1 sdf 8:80 active ready running ocr (360022a11000a187faf44b41000000012) dm-4 HUASY,S6800T size=80G features='0' hwhandler='0' wp=rw |-+- policy='round-robin 0' prio=1 status=active | `- 3:0:0:2 sdd 8:48 active ready running `-+- policy='round-robin 0' prio=1 status=enabled `- 4:0:0:2 sdg 8:96 active ready running

4、配置

1. /etc/multipath/bindings

mulitpath 默认生成的设备名位mpathx 这样的设备名。这样的名字会保存在/etc/multipath/bindings文件里,文件里由设备名和wwid的对应关系，如果在配置rac时采用默认名字的方式，如两本不一致请查看此文件 。Red 6的文件在/etc/multipath/bindings，Red 5在 /var/lib/m ultipath/bindings.

# cat /etc/multipath/bindings # Multipath bindings, Version : 1.0 # NOTE: this file is automatically maintained by the multipath program. # You should not need to edit this file in normal circumstances. # # Format: # alias wwid # mpatha 36b8ca3a0f8f4c5001adebca406dbbfc4 mpathd 360022a11000a187faf44b43900000013 mpathb 360022a11000a187f21673bce00000041 mpathc 360022a11000a187f21673b7000000040 mpathe 360022a11000a187fc76dc61000000014 mpathf 360022a11000a187fc76dc63800000015

2. etc/multipath/wwids

还有个文件就是 etc/multipath/wwids,这个文件显示wwid

# cat /etc/multipath/wwids # Multipath wwids, Version : 1.0 # NOTE: This file is automatically maintained by multipath and multipathd. # You should not need to edit this file in normal circumstances. # # Valid WWIDs: /360022a11000a187faf44b43900000013/ /360022a11000a187f2168e465000000f6/ /360022a11000a187f2168e420000000f5/ /360022a11000a187f21673bce00000041/ /360022a11000a187f21673b7000000040/ /360022a11000a187fc76dc61000000014/ /360022a11000a187fc76dc63800000015/

3. /etc/multipath.conf

这个文件是multipath主要的配置,可以采用默认配置文件，建议进行配置，最简单的配置就想

multipath { wwid 360050763008101d4e00000000000000a alias DATA03

5、配置权限

在6.2之前配置multipath设备的权限只需要在设备配置里增加uid,gid,mode就可以

uid 1100 #uid
gid 1020 #gid
如

multipath { wwid 360050763008101d4e00000000000000a alias DATA03 uid 501 #uid gid 501 #gid

}

在6.2之后配置multipath配置文件里去掉uid,gid,mode这三个参数，需要使用udev使用,示例文件在/usr/share/doc/device-mapper-version中有一个模板文件,
名为12-dm-permissions.rules,您可以使用它并将其放在 /etc/udev/rules.d 目录中使其生效

[root@rac01 rules.d]#  vi 12-dm-permissions.rules
 ENV{DM_NAME}=="ocr", OWNER:="grid", GROUP:="asmadmin", MODE:="660"
 ENV{DM_NAME}=="data01", OWNER:="grid", GROUP:="asmadmin", MODE:="660"
 ENV{DM_NAME}=="data02", OWNER:="grid", GROUP:="asmadmin", MODE:="660"

在redhat6 multipath 取消了/dev/mpath 目录,并且在mapper可以看到设备是链接方式,在5上看不出来

• redhat5

[root@xxx goldengate]# ls -l /dev/mapper/sd400G* brw-rw---- 1 root disk 253, 0 Jun 25 14:44 /dev/mapper/sd400G brw-rw---- 1 root disk 253, 5 Jun 25 15:47 /dev/mapper/sd400Gp1

• redhat6

[root@xhdb-paas01 ~]# ls -l /dev/mapper/ total 0 crw-rw---- 1 root root 10, 236 May 4 10:19 control lrwxrwxrwx 1 root root 7 May 4 10:45 mpathb -> ../dm-2 lrwxrwxrwx 1 root root 7 May 4 10:45 mpathc -> ../dm-3 lrwxrwxrwx 1 root root 7 May 4 10:26 ocr -> ../dm-4

在启动udev后,查看/dev/mapper/下的文件还会是root权限因为是软链接,得查看/dev/dm-n想设备

[root@xhdb-paas01 ~]# ls -l /dev/dm-*
brw-rw---- 1 root disk     252,  0 May  4 10:19 /dev/dm-0
brw-rw---- 1 root disk     252,  1 May  4 10:19 /dev/dm-1
brw-rw---- 1 root disk     252, 10 May  4 10:19 /dev/dm-10
brw-rw---- 1 root disk     252,  2 May  4 10:45 /dev/dm-2
brw-rw---- 1 root disk     252,  3 May  4 10:45 /dev/dm-3
brw-rw---- 1 grid asmadmin 252,  4 May  4 14:05 /dev/dm-4
brw-rw---- 1 root disk     252,  9 May  4 10:19 /dev/dm-9