一、多路径解释
多路径,顾名思义就是有多种选择的路径。在SAN或IPSAN环境,主机和存储之间外加了光纤交换机,这就导致主机和存储之间交换速度和效率增强,一条路径肯定是不行的,也是不安全不稳定的。多路径就是要来解决从主机到磁盘之间最快,最高效的问题。主要实现如下几个功能
多路径之前一直是存储厂商负责解决,竟来被拆分出来单独卖钱了。
构架基本是这样的:存储,多路径软件,光纤交换机,主机,主机系统。
二、LINUX下的multipath
1、查看是否自带安装?
2、安装
3、配置
blacklist {
devnode '^sda'
}
defaults {
user_friendly_names no
}
multipaths {
multipath {
wwid 14945540000000000a67854c6270b4359c66c272e2f356321
alias iscsi-dm0
path_grouping_policy multibus
path_checker tur
path_selector 'round-robin 0'
}
multipath {
wwid 14945540000000000dcca2eda91d70b81edbcfce2357f99ee
alias iscsi-dm1
path_grouping_policy multibus
path_checker tur
path_selector 'round-robin 0'
}
multipath {
wwid 1494554000000000020f763489c165561101813333957ed96
alias iscsi-dm2
path_grouping_policy multibus
path_checker tur
path_selector 'round-robin 0'
}
multipath {
wwid 14945540000000000919ca813020a195422ba3663e1f03cc3
alias iscsi-dm3
path_grouping_policy multibus
path_checker tur
path_selector 'round-robin 0'
}
}
devices {
device {
vendor 'iSCSI-Enterprise'
product 'Virtual disk'
path_grouping_policy multibus
getuid_callout '/sbin/scsi_id -g -u -s /block/%n'
path_checker readsector0
path_selector 'round-robin 0'
}
}
4、命令
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | [root @web2 ~]# multipath -h multipath-tools v0. 4.7 ( 03 / 12 , 2006 ) Usage: multipath [-v level] [-d] [-h|-l|-ll|-f|-F|-r] [-p failover|multibus|group_by_serial|group_by_prio] [device] -v level verbosity level 0 no output 1 print created devmap names only 2 default verbosity 3 print debug information -h print this usage text -b file bindings file location -d dry run, do not create or update devmaps -l show multipath topology (sysfs and DM info) -ll show multipath topology (maximum info) -f flush a multipath device map -F flush all multipath device maps -r force devmap reload -p policy force all maps to specified policy : failover 1 path per priority group multibus all paths in 1 priority group group_by_serial 1 priority group per serial group_by_prio 1 priority group per priority lvl group_by_node_name 1 priority group per target node device limit scope to the device's multipath (udev-style $DEVNAME reference, eg /dev/sdb or major:minor or a device map name) [root @web2 ~]# |
5、启动关闭
6、如何获取wwid
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | 1 、 [root @vxfs01 ~]# cat /var/lib/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 # mpath0 36006016051d50e0035744871c912de11 mpath1 36006016051d50e0034744871c912de11 mpath2 36006016051d50e0032744871c912de11 mpath3 36006016051d50e0039744871c912de11 mpath4 36006016051d50e003a744871c912de11 2 、 [root @vxfs01 ~]# multipath -v3 |grep 3600 sdb: uid = 36006016051d50e003a744871c912de11 (callout) sdc: uid = 36006016051d50e003a744871c912de11 (callout) sdd: uid = 36006016051d50e003a744871c912de11 (callout) sde: uid = 36006016051d50e003a744871c912de11 (callout) 36006016051d50e003a744871c912de11 1 : 0 : 0 : 0 sdb 8 : 16 0 [undef][ready] DGC,RAI 36006016051d50e003a744871c912de11 1 : 0 : 1 : 0 sdc 8 : 32 1 [undef][ready] DGC,RAI 36006016051d50e003a744871c912de11 2 : 0 : 0 : 0 sdd 8 : 48 1 [undef][ready] DGC,RAI 36006016051d50e003a744871c912de11 2 : 0 : 1 : 0 sde 8 : 64 0 [undef][ready] DGC,RAI Found matching wwid [36006016051d50e003a744871c912de11] in bindings file. |
比较详细的文字:
http://zhumeng8337797.blog.163.com/blog/static/1007689142013416111534352/
http://blog.csdn.net/wuweilong/article/details/14184097
RHEL官网资料:
http://www.prudentwoo.com/wp-content/uploads/downloads/2013/11/Red_Hat_Enterprise_Linux-5-DM_Multipath-en-US.pdf
http://www.prudentwoo.com/wp-content/uploads/downloads/2013/11/Red_Hat_Enterprise_Linux-5-DM_Multipath-zh-CN.pdf
http://www.prudentwoo.com/wp-content/uploads/downloads/2013/11/Red_Hat_Enterprise_Linux-6-DM_Multipath-en-US.pdf
http://www.prudentwoo.com/wp-content/uploads/downloads/2013/11/Red_Hat_Enterprise_Linux-6-DM_Multipath-zh-CN.pdf
联系客服