linux存储多路径
A. linux iscsi开启多路径什么样子
Linux多路径指的是除了主机和硬盘一条路径的连接，还包括了主机和网络服务器的连接形成的主机一对多的路径连接关系。通过多路径的连接，实现了磁盘的虚拟化。
B. Linux多路径配置
如果使用了多路径方案，可以直接使用multipath绑定设备名不需要用到asmlib或UDEV请直接参考文档：Configuringnon-(11.1.0,11.2.0)onRHEL5/OL5[ID605828.1][root@vrh1~]#foriin`cat/proc/partitions|awk'{print$4}'|grepsd|grep[a-z]$`;doecho"###$i:`scsi_id-g-u-s/block/$i`";done###sda:SATA_VBOX_HARDDISK_VB83d4445f-b8790695_###sdb:SATA_VBOX_HARDDISK_VB0db2f233-269850e0_###sdc:SATA_VBOX_HARDDISK_VBa56f2571-0dd27b33_###sdd:SATA_VBOX_HARDDISK_VBf6b74ff7-871d1de8_###sde:SATA_VBOX_HARDDISK_VB5a531910-25f4eb9a_###sdf:SATA_VBOX_HARDDISK_VB4915e6e3-737b312e_###sdg:SATA_VBOX_HARDDISK_VB512c8f75-37f4a0e9_###sdh:SATA_VBOX_HARDDISK_VBc0115ef6-a48bc15d_###sdi:SATA_VBOX_HARDDISK_VB3a556907-2b72391d_###sdj:SATA_VBOX_HARDDISK_VB7ec8476c-08641bd4_###sdk:SATA_VBOX_HARDDISK_VB743e1567-d0009678_[root@vrh1~]#grep-v^#/etc/multipath.confdefaults{user_friendly_namesyes}defaults{udev_dir/devpolling_interval10selector"round-robin0"path_grouping_policyfailovergetuid_callout"/sbin/scsi_id-g-u-s/block/%n"prio_callout/bin/truepath_checkerreadsector0rr_min_io100rr_#no_path_retryfailuser_friendly_nameyes}devnode_blacklist{devnode"^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"devnode"^hd[a-z]"devnode"^cciss!c[0-9]d[0-9]*"}multipaths{multipath{wwidSATA_VBOX_HARDDISK_VB0db2f233-269850e0_aliasvoting1path_grouping_policyfailover}multipath{wwidSATA_VBOX_HARDDISK_VBa56f2571-0dd27b33_aliasvoting2path_grouping_policyfailover}multipath{wwidSATA_VBOX_HARDDISK_VBf6b74ff7-871d1de8_aliasvoting3path_grouping_policyfailover}multipath{wwidSATA_VBOX_HARDDISK_VB5a531910-25f4eb9a_aliasocr1path_grouping_policyfailover}multipath{wwidSATA_VBOX_HARDDISK_VB4915e6e3-737b312e_aliasocr2path_grouping_policyfailover}multipath{wwidSATA_VBOX_HARDDISK_VB512c8f75-37f4a0e9_aliasocr3path_grouping_policyfailover}}[root@vrh1~]#multipath[root@vrh1~]#multipath-llmpath2(SATA_VBOX_HARDDISK_VB3a556907-2b72391d_)dm-9ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-8:0:0:0sdi8:128activereadyrunningmpath1(SATA_VBOX_HARDDISK_VBc0115ef6-a48bc15d_)dm-8ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-7:0:0:0sdh8:112activereadyrunningocr3(SATA_VBOX_HARDDISK_VB512c8f75-37f4a0e9_)dm-7ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-6:0:0:0sdg8:96activereadyrunningocr2(SATA_VBOX_HARDDISK_VB4915e6e3-737b312e_)dm-6ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-5:0:0:0sdf8:80activereadyrunningocr1(SATA_VBOX_HARDDISK_VB5a531910-25f4eb9a_)dm-5ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-4:0:0:0sde8:64activereadyrunningvoting3(SATA_VBOX_HARDDISK_VBf6b74ff7-871d1de8_)dm-4ATA,VBOXHARDDISKsize=40Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-3:0:0:0sdd8:48activereadyrunningvoting2(SATA_VBOX_HARDDISK_VBa56f2571-0dd27b33_)dm-3ATA,VBOXHARDDISKsize=40Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-2:0:0:0sdc8:32activereadyrunningvoting1(SATA_VBOX_HARDDISK_VB0db2f233-269850e0_)dm-2ATA,VBOXHARDDISKsize=40Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-1:0:0:0sdb8:16activereadyrunningmpath4(SATA_VBOX_HARDDISK_VB743e1567-d0009678_)dm-11ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-10:0:0:0sdk8:160activereadyrunningmpath3(SATA_VBOX_HARDDISK_VB7ec8476c-08641bd4_)dm-10ATA,VBOXHARDDISKsize=5.0Gfeatures='0'hwhandler='0'wp=rw`-+-policy='round-robin0'prio=1status=active`-9:0:0:0sdj8:144activereadyrunning[root@vrh1~]#dmsetupls|sortmpath1(253,8)mpath2(253,9)mpath3(253,10)mpath4(253,11)ocr1(253,5)ocr2(253,6)ocr3(253,7)VolGroup00-LogVol00(253,0)VolGroup00-LogVol01(253,1)voting1(253,2)voting2(253,3)voting3(253,4)[root@vrh1~]#ls-l/dev/mapper/*crw-------1rootroot10,62Oct1709:58/dev/mapper/controlbrw-rw----1rootdisk253,8Oct1900:11/dev/mapper/mpath1brw-rw----1rootdisk253,9Oct1900:11/dev/mapper/mpath2brw-rw----1rootdisk253,10Oct1900:11/dev/mapper/mpath3brw-rw----1rootdisk253,11Oct1900:11/dev/mapper/mpath4brw-rw----1rootdisk253,5Oct1900:11/dev/mapper/ocr1brw-rw----1rootdisk253,6Oct1900:11/dev/mapper/ocr2brw-rw----1rootdisk253,7Oct1900:11/dev/mapper/ocr3brw-rw----1rootdisk253,0Oct1709:58/dev/mapper/VolGroup00-LogVol00brw-rw----1rootdisk253,1Oct1709:58/dev/mapper/VolGroup00-LogVol01brw-rw----1rootdisk253,2Oct1900:11/dev/mapper/voting1brw-rw----1rootdisk253,3Oct1900:11/dev/mapper/voting2brw-rw----1rootdisk253,4Oct1900:11/dev/mapper/voting3[root@vrh1~]#ls-l/dev/dm*brw-rw----1rootroot253,0Oct1709:58/dev/dm-0brw-rw----1rootroot253,1Oct1709:58/dev/dm-1brw-rw----1rootroot253,10Oct1900:11/dev/dm-10brw-rw----1rootroot253,11Oct1900:11/dev/dm-11brw-rw----1rootroot253,2Oct1900:11/dev/dm-2brw-rw----1rootroot253,3Oct1900:11/dev/dm-3brw-rw----1rootroot253,4Oct1900:11/dev/dm-4brw-rw----1rootroot253,5Oct1900:11/dev/dm-5brw-rw----1rootroot253,6Oct1900:11/dev/dm-6brw-rw----1rootroot253,7Oct1900:11/dev/dm-7brw-rw----1rootroot253,8Oct1900:11/dev/dm-8brw-rw----1rootroot253,9Oct1900:11/dev/dm-9[root@vrh1~]#ls-l/dev/disk/by-id/:58scsi-SATA_VBOX_HARDDISK_VB0db2f233-269850e0->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB3a556907-2b72391d->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB4915e6e3-737b312e->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB512c8f75-37f4a0e9->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB5a531910-25f4eb9a->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB743e1567-d0009678->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB7ec8476c-08641bd4->../../asm-:58scsi-SATA_VBOX_HARDDISK_VB83d4445f-b8790695->../../:58scsi-SATA_VBOX_HARDDISK_VB83d4445f-b8790695-part1->../../:58scsi-SATA_VBOX_HARDDISK_VB83d4445f-b8790695-part2->../../:58scsi-SATA_VBOX_HARDDISK_VBa56f2571-0dd27b33->../../asm-:58scsi-SATA_VBOX_HARDDISK_VBc0115ef6-a48bc15d->../../asm-:58scsi-SATA_VBOX_HARDDISK_VBf6b74ff7-871d1de8->../../asm-diskdReportAbuseLike(0)2.Re:asm磁盘使用链路聚合设备名，IO性能只有非聚合设备的1/6!LiuMaclean(刘相兵)ExpertLiuMaclean(刘相兵)Jul21,201311:09AM(inresponseto13628)step1:[oracle@vrh8mapper]$cat/etc/multipath.confmultipaths{multipath{wwidSATA_VBOX_HARDDISK_VBf6b74ff7-871d1de8_aliasasm-disk1mode660uid501gid503}multipath{wwidSATA_VBOX_HARDDISK_VB0db2f233-269850e0_aliasasm-disk2mode660uid501gid503}multipath{wwidSATA_VBOX_HARDDISK_VBa56f2571-0dd27b33_aliasasm-disk3mode660uid501gid503}}第二步：第三步：[oracle@vrh8mapper]$ls-l/dev/mapper/asm-disk*brw-rw----1gridasmadmin253,4Jul2107:02/dev/mapper/asm-disk1brw-rw----1gridasmadmin253,2Jul2107:02/dev/mapper/asm-disk2brw-rw----1gridasmadmin253,3Jul2107:02/dev/mapper/asm-disk3
C. 了解Linux下多路径设备怎样分区么
安装的时候可以手动分区
安装好后
用代码分区
代码详细解析见网页链接
D. Linux系统怎么配置多路径
是要挂存储吗？你需要安装multipath，然后配置文件是:/etc/multipath.conf
E. linux系统装好多路径软件时，还可以通过fdisk -l 查看到多条路径吗
fdisk -l看到的是逻辑设备。譬如你存储映射到主机的一个LUN，经过两条路径到主机上，那么在主机上fdisk -l就会看到两块逻辑上的磁盘，事实上这两块磁盘是同一个物理设备（对于主机来说，LUN是物理设备），通过multipath -ll看到的是一个物理设备下的实际的两条path。
F. linux多路径新lun怎么使用新lun
可通过emcpower display dev=all查看系统识别到磁盘在存储中LUN Name，从而对应存储中的LUN。
G. 请教linux多路径管理，维护切换路径问题
普通的电脑主机都是一个硬盘挂接到一个总线上，这里是一对一的关系。而到了有光纤组成的SAN环境，或者由iSCSI组成的IPSAN环境，由于主机和存储通过了光纤交换机或者多块网卡及IP来连接，这样的话，就构成了多对多的关系。也就是说，主机到存储可以有多条路径可以选择。主机到存储之间的IO由多条路径可以选择。每个主机到所对应的存储可以经过几条不同的路径，如果是同时使用的话，I/O流量如何分配？其中一条路径坏掉了，如何处理？还有在操作系统的角度来看，每条路径，操作系统会认为是一个实际存在的物理盘，但实际上只是通向同一个物理盘的不同路径而已，这样是在使用的时候，就给用户带来了困惑。多路径软件就是为了解决上面的问题应运而生的。
H. linux多路径mpath怎么修改名称
Linux下多路径Multipath的简单配置
1、启用Multipath：
（1）启动multipathd服务
#service
multipathd
start
或者
#/etc/init.d/multipathd
start
（2）修改multipath配置文件/etc/multipath.conf：
a
默认情况下所以的设备都在multipath的黑名单中，所以即使启动了multipathd服务并加在了内核模块，multipath也不会对链路进行聚合，找到下面的3行并注释掉（在行首加上#号）
#devnode_blacklist
{
#
devnode
"*"
#}
b
默认情况下multipath生成dm设备之后，会同时在/dev/mapper/下生成以磁盘wwid为名的符号链接指向对应的dm设备。如果想生成mpath设备，则需要打开user_friendly_names选项，将配置文件中下面3行的注释取消（去掉行首的#号）
defaults
{
user_friendly_names
yes
}
（3）重启multipathd服务（修改multipath.conf文件之后都应该重启multipath服务）
（4）扫描磁盘
#multipath
-v2
使用上面命令之后，系统中会出现链路聚合之后的dm设备，同时也会在/dev/mapper/、/dev/mpath/目录下生成相应的设备。
查看multipath拓扑结构
#multipath
-ll
另外一个重要的文件是/var/lib/multipath/bindings，这个文件中是磁盘的别名和wwid的对应关系，典型的例子是：
mpath0
（5）需要注意的问题，multipath也会为本地的磁盘生成相应的dm设备，所以需要在multipath.conf中将本地磁盘加入到黑名单，配置的方法可以参考下面的示例
devnode_blacklist
{
wwid
devnode
"^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode
"^hd[a-z]"
}
如上例所示，可以通过wwid或者设备名将本地磁盘加入到黑名单中。
2、固定multipath设备的命名：
通过wwid和设备别名一一对应的方式固定multipath设备的名称，这些和别名对应的设备会被创建到/dev/mapper/目录下，使用时直接使用这个目录的的设备。
（1）通过/var/lib/multipath/bindings可以获取所有磁盘的wwid，确定每个磁盘的别名之后，在/etc/multipath.conf中的multipaths段中加入相应的配置，如将wwid为的磁盘命名为etl01，wwid为的磁盘命名为etl02，配置文件如下所示
multipaths
{
multipath
{
wwid
alias
etl01
}
multipath
{
wwid
alias
etl02
}
}
（2）配置完成之后，重启multipathd服务，使用下面的命令清空已有的multipath记录
#multipath
-F
然后使用multipath
-v2重新扫描设备，这时会在/dev/mapper/目录下生成和别名对应的设备文件。
#ls
/dev/mapper/
control
etl01
eth02
（3）如果多台服务器的存储链路完全相同，并希望各服务器上同一磁盘的设备名相同，可以在一台服务器上配置好别名绑定之后，将multipaths
{
}中间的配置复制到其他服务器，这样各台服务器/dev/mapper/下面的设备将会保持一致。
I. linux什么情况下用到多路径
1、安装多路径软件包：
device-mapper-1.02.67-2.el5
device-mapper-event-1.02.67.2.el5
device-mapper-multipath-0.4.7-48.el5
[plain] view plain print?
[root@RKDB01 Server]# rpm -ivh device-mapper-1.02.67-2.el5.x86_64.rpm
warning: device-mapper-1.02.67-2.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
package device-mapper-1.02.67-2.el5.x86_64 is already installed
[root@RKDB01 Server]# rpm -ivh device-mapper-event-1.02.67-2.el5.x86_64.rpm
warning: device-mapper-event-1.02.67-2.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
package device-mapper-event-1.02.67-2.el5.x86_64 is already installed
[root@RKDB01 Server]# rpm -ivh device-mapper-multipath-0.4.7-48.el5.x86_64.rpm
warning: device-mapper-multipath-0.4.7-48.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 37017186
Preparing... ########################################### [100%]
package device-mapper-multipath-0.4.7-48.el5.x86_64 is already installed
2、设置开机启动，并检查安装包是否正常：
chkconfig --level 345 multipathd on
lsmod |grep dm_multipath
[plain] view plain print?
[root@RKDB01 Server]# chkconfig --level 345 multipathd on
[root@RKDB01 Server]# lsmod |grep dm_multipath
dm_multipath 58969 0
scsi_dh 42561 1 dm_multipath
dm_mod 102417 4 dm_mirror,dm_multipath,dm_raid45,dm_log
[root@RKDB01 Server]#
3、配置multipathd 使其正常工作，编辑/etc/multipath.conf，开放如下内容：
[plain] view plain print?
defaults {
udev_dir /dev
polling_interval 10
selector "round-robin 0"
path_grouping_policy multibus
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
prio_callout none
path_checker readsector0
rr_min_io 100
max_fds 8192
rr_weight priorities
failback immediate
no_path_retry fail
user_friendly_names yes
}
blacklist {
wwid 26353900f02796769
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^hd[a-z]"
}
4、并关闭如下内容
[plain] view plain print?
#blacklist {
# devnode "*"
#}
#defaults {
27 # user_friendly_names yes
28 #}
5、完成之后执行如下命令发现多路径：
[plain] view plain print?
[root@RKDB01 Server]# modprobe dm-multipath
[root@RKDB01 Server]# multipath -F
[root@RKDB01 Server]# multipath dm-multipath
[root@RKDB01 Server]# multipath dm-round-robin
[root@RKDB01 Server]# service multipathd restart
正在关闭multipathd 端口监控程序： [确定]
正在启动守护进程multipathd： [确定]
[root@RKDB01 Server]# multipath -v2
[root@RKDB01 Server]# multipath -v2
[root@RKDB01 Server]# multipath -ll
mpath1 () dm-0 TOYOU,NetStor_iSUM510
[size=3.3T][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=2][ena bled]
\_ 1:0:0:0 sdb 8:16 [failed][ready]
\_ 1:0:1:0 sdc 8:32 [failed][ready]
[root@RKDB01 Server]#
6、重启服务器后，我们可以看到多路径信息了：
[plain] view plain print?
[root@RKDB01 ~]# ll /dev/mapper/
总计 0
crw------- 1 root root 10, 60 11-05 22:35 control
brw-rw---- 1 root disk 253, 0 11-05 22:35 mpath1
brw-rw---- 1 root disk 253, 1 11-05 22:35 mpath2
[root@RKDB01 ~]# multipath -ll
mpath2 () dm-1 TOYOU,NetStor_iSUM510
[size=3.2T][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=2][active]
\_ 1:0:0:1 sdc 8:32 [active][ready]
\_ 1:0:1:1 sde 8:64 [active][ready]
mpath1 () dm-0 TOYOU,NetStor_iSUM510
[size=20G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=2][active]
\_ 1:0:0:0 sdb 8:16 [active][ready]
\_ 1:0:1:0 sdd 8:48 [active][ready]
7、通过fdisk 看可以生成了DM-0/DM-1两个盘，正是上面sdc/sde,sdb/sdd多路径后出来的：
[plain] view plain print?
[root@RKDB01 ~]# fdisk -l
Disk /dev/sda: 299.4 GB, 299439751168 bytes
255 heads, 63 sectors/track, 36404 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 38 305203+ 83 Linux
/dev/sda2 39 13092 104856255 83 Linux
/dev/sda3 13093 19619 52428127+ 83 Linux
/dev/sda4 19620 36404 134825512+ 5 Extended
/dev/sda5 19620 26146 52428096 83 Linux
/dev/sda6 26147 28757 20972826 83 Linux
/dev/sda7 28758 30324 12586896 82 Linux swap / Solaris
/dev/sda8 30325 36404 48837568+ 83 Linux
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table
Disk /dev/sdc: 3568.4 GB, 3568429957120 bytes
255 heads, 63 sectors/track, 433836 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdc doesn't contain a valid partition table
Disk /dev/sdd: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdd doesn't contain a valid partition table
Disk /dev/sde: 3568.4 GB, 3568429957120 bytes
255 heads, 63 sectors/track, 433836 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sde doesn't contain a valid partition table
Disk /dev/dm-0: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/dm-0 doesn't contain a valid partition table
Disk /dev/dm-1: 3568.4 GB, 3568429957120 bytes
255 heads, 63 sectors/track, 433836 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/dm-1 doesn't contain a valid partition table
Disk /dev/sdf: 4009 MB, 4009754624 bytes
255 heads, 63 sectors/track, 487 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdf4 * 1 488 3915744+ b W95 FAT32
Partition 4 has different physical/logical endings:
phys=(486, 254, 63) logical=(487, 125, 22)
[root@RKDB01 ~]#
8、我们同时也可以在/dev/mapper目录中查看到多路径映射的信息：
[plain] view plain print?
[root@RKDB01 ~]# ll /dev/mapper/
总计 0
crw------- 1 root root 10, 60 11-06 00:49 control
brw-rw---- 1 root disk 253, 2 11-06 00:49 data-data001
brw-rw---- 1 root disk 253, 0 11-06 00:49 mpath1
brw-rw---- 1 root disk 253, 1 11-06 00:49 mpath2
J. 如何使用Linux自带多路径DM
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
故障的切换和恢复
IO流量的负载均衡
磁盘的虚拟化
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？
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[root@web2 multipath]# rpm -qa|grep device
device-mapper-1.02.39-1.el5
device-mapper-1.02.39-1.el5
device-mapper-multipath-0.4.7-34.el5
device-mapper-event-1.02.39-1.el5
[root@web2 multipath]#
2、安装
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rpm -ivh device-mapper-1.02.39-1.el5.rpm #安装映射包
rpm -ivh device-mapper-multipath-0.4.7-34.el5.rpm #安装多路径包
外加加入开机启动
chkconfig –level 2345 multipathd on #设置成开机自启动multipathd
lsmod |grep dm_multipath #来检查安装是否正常
3、配置
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# on the default devices.
blacklist {
devnode "^(ram|raw|loop|fd|md|dm-|sr|sr|scd|st)[0-9]*"
devnode "^hd[a-z]"
}
devices {
device {
vendor "HP"
path_grouping_policy multibus
features "1 queue_if_no_path"
path_checker readsector()
failback immediate
}
}<br><br>完整的配置如下：
blacklist {
devnode "^sda"
}
defaults {
user_friendly_names no
}
multipaths {
multipath {
wwid
alias iscsi-dm0
path_grouping_policy multibus
path_checker tur
path_selector "round-robin 0"
}
multipath {
wwid
alias iscsi-dm1
path_grouping_policy multibus
path_checker tur
path_selector "round-robin 0"
}
multipath {
wwid
alias iscsi-dm2
path_grouping_policy multibus
path_checker tur
path_selector "round-robin 0"
}
multipath {
wwid
alias iscsi-dm3
path_grouping_policy multibus
path_checker tur
path_selector "round-robin 0"
}
}
devices {
device {
vendor "iSCSI-Enterprise"
proct "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
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[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
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# /etc/init.d/multipathd start #开启mulitipath服务
service multipath start
service multipath restart
service multipath shutdown
6、如何获取wwid
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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
mpath1
mpath2
mpath3
mpath4
2、
[root@vxfs01 ~]# multipath -v3 |grep 3600
sdb: uid = (callout)
sdc: uid = (callout)
sdd: uid = (callout)
sde: uid = (callout)
1:0:0:0 sdb 8:16 0 [undef][ready] DGC,RAI
1:0:1:0 sdc 8:32 1 [undef][ready] DGC,RAI
2:0:0:0 sdd 8:48 1 [undef][ready] DGC,RAI
2:0:1:0 sde 8:64 0 [undef][ready] DGC,RAI
Found matching wwid [] 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