linux存儲多路徑
A. linux iscsi開啟多路徑什麼樣子
Linux多路徑指的是除了主機和硬碟一條路徑的連接，還包括了主機和網路伺服器的連接形成的主機一對多的路徑連接關系。通過多路徑的連接，實現了磁碟的虛擬化。
B. Linux多路徑配置
如果使用了多路徑方案，可以直接使用multipath綁定設備名不需要用到asmlib或UDEV請直接參考文檔：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磁碟使用鏈路聚合設備名，IO性能只有非聚合設備的1/6!LiuMaclean(劉相兵)ExpertLiuMaclean(劉相兵)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下多路徑設備怎樣分區么
安裝的時候可以手動分區
安裝好後
用代碼分區
代碼詳細解析見網頁鏈接
D. Linux系統怎麼配置多路徑
是要掛存儲嗎？你需要安裝multipath，然後配置文件是:/etc/multipath.conf
E. linux系統裝好多路徑軟體時，還可以通過fdisk -l 查看到多條路徑嗎
fdisk -l看到的是邏輯設備。譬如你存儲映射到主機的一個LUN，經過兩條路徑到主機上，那麼在主機上fdisk -l就會看到兩塊邏輯上的磁碟，事實上這兩塊磁碟是同一個物理設備（對於主機來說，LUN是物理設備），通過multipath -ll看到的是一個物理設備下的實際的兩條path。
F. linux多路徑新lun怎麼使用新lun
可通過emcpower display dev=all查看系統識別到磁碟在存儲中LUN Name，從而對應存儲中的LUN。
G. 請教linux多路徑管理，維護切換路徑問題
普通的電腦主機都是一個硬碟掛接到一個匯流排上，這里是一對一的關系。而到了有光纖組成的SAN環境，或者由iSCSI組成的IPSAN環境，由於主機和存儲通過了光纖交換機或者多塊網卡及IP來連接，這樣的話，就構成了多對多的關系。也就是說，主機到存儲可以有多條路徑可以選擇。主機到存儲之間的IO由多條路徑可以選擇。每個主機到所對應的存儲可以經過幾條不同的路徑，如果是同時使用的話，I/O流量如何分配？其中一條路徑壞掉了，如何處理？還有在操作系統的角度來看，每條路徑，操作系統會認為是一個實際存在的物理盤，但實際上只是通向同一個物理盤的不同路徑而已，這樣是在使用的時候，就給用戶帶來了困惑。多路徑軟體就是為了解決上面的問題應運而生的。
H. linux多路徑mpath怎麼修改名稱
Linux下多路徑Multipath的簡單配置
1、啟用Multipath：
（1）啟動multipathd服務
#service
multipathd
start
或者
#/etc/init.d/multipathd
start
（2）修改multipath配置文件/etc/multipath.conf：
a
默認情況下所以的設備都在multipath的黑名單中，所以即使啟動了multipathd服務並加在了內核模塊，multipath也不會對鏈路進行聚合，找到下面的3行並注釋掉（在行首加上#號）
#devnode_blacklist
{
#
devnode
"*"
#}
b
默認情況下multipath生成dm設備之後，會同時在/dev/mapper/下生成以磁碟wwid為名的符號鏈接指向對應的dm設備。如果想生成mpath設備，則需要打開user_friendly_names選項，將配置文件中下面3行的注釋取消（去掉行首的#號）
defaults
{
user_friendly_names
yes
}
（3）重啟multipathd服務（修改multipath.conf文件之後都應該重啟multipath服務）
（4）掃描磁碟
#multipath
-v2
使用上面命令之後，系統中會出現鏈路聚合之後的dm設備，同時也會在/dev/mapper/、/dev/mpath/目錄下生成相應的設備。
查看multipath拓撲結構
#multipath
-ll
另外一個重要的文件是/var/lib/multipath/bindings，這個文件中是磁碟的別名和wwid的對應關系，典型的例子是：
mpath0
（5）需要注意的問題，multipath也會為本地的磁碟生成相應的dm設備，所以需要在multipath.conf中將本地磁碟加入到黑名單，配置的方法可以參考下面的示例
devnode_blacklist
{
wwid
devnode
"^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode
"^hd[a-z]"
}
如上例所示，可以通過wwid或者設備名將本地磁碟加入到黑名單中。
2、固定multipath設備的命名：
通過wwid和設備別名一一對應的方式固定multipath設備的名稱，這些和別名對應的設備會被創建到/dev/mapper/目錄下，使用時直接使用這個目錄的的設備。
（1）通過/var/lib/multipath/bindings可以獲取所有磁碟的wwid，確定每個磁碟的別名之後，在/etc/multipath.conf中的multipaths段中加入相應的配置，如將wwid為的磁碟命名為etl01，wwid為的磁碟命名為etl02，配置文件如下所示
multipaths
{
multipath
{
wwid
alias
etl01
}
multipath
{
wwid
alias
etl02
}
}
（2）配置完成之後，重啟multipathd服務，使用下面的命令清空已有的multipath記錄
#multipath
-F
然後使用multipath
-v2重新掃描設備，這時會在/dev/mapper/目錄下生成和別名對應的設備文件。
#ls
/dev/mapper/
control
etl01
eth02
（3）如果多台伺服器的存儲鏈路完全相同，並希望各伺服器上同一磁碟的設備名相同，可以在一台伺服器上配置好別名綁定之後，將multipaths
{
}中間的配置復制到其他伺服器，這樣各台伺服器/dev/mapper/下面的設備將會保持一致。
I. linux什麼情況下用到多路徑
1、安裝多路徑軟體包：
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、設置開機啟動，並檢查安裝包是否正常：
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，編輯/etc/multipath.conf，開放如下內容：
[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、並關閉如下內容
[plain] view plain print?
#blacklist {
# devnode "*"
#}
#defaults {
27 # user_friendly_names yes
28 #}
5、完成之後執行如下命令發現多路徑：
[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
正在關閉multipathd 埠監控程序： [確定]
正在啟動守護進程multipathd： [確定]
[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、重啟伺服器後，我們可以看到多路徑信息了：
[plain] view plain print?
[root@RKDB01 ~]# ll /dev/mapper/
總計 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、通過fdisk 看可以生成了DM-0/DM-1兩個盤，正是上面sdc/sde,sdb/sdd多路徑後出來的：
[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、我們同時也可以在/dev/mapper目錄中查看到多路徑映射的信息：
[plain] view plain print?
[root@RKDB01 ~]# ll /dev/mapper/
總計 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自帶多路徑DM
一、多路徑解釋
多路徑，顧名思義就是有多種選擇的路徑。在SAN或IPSAN環境，主機和存儲之間外加了光纖交換機，這就導致主機和存儲之間交換速度和效率增強，一條路徑肯定是不行的，也是不安全不穩定的。多路徑就是要來解決從主機到磁碟之間最快，最高效的問題。主要實現如下幾個功能
故障的切換和恢復
IO流量的負載均衡
磁碟的虛擬化
多路徑之前一直是存儲廠商負責解決，竟來被拆分出來單獨賣錢了。
構架基本是這樣的：存儲，多路徑軟體，光纖交換機，主機，主機系統。
二、LINUX下的multipath
1、查看是否自帶安裝？
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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、安裝
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rpm -ivh device-mapper-1.02.39-1.el5.rpm #安裝映射包
rpm -ivh device-mapper-multipath-0.4.7-34.el5.rpm #安裝多路徑包
外加加入開機啟動
chkconfig –level 2345 multipathd on #設置成開機自啟動multipathd
lsmod |grep dm_multipath #來檢查安裝是否正常
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、啟動關閉
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# /etc/init.d/multipathd start #開啟mulitipath服務
service multipath start
service multipath restart
service multipath shutdown
6、如何獲取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.
比較詳細的文字：
http://zhumeng8337797.blog.163.com/blog/static/1007689142013416111534352/
http://blog.csdn.net/wuweilong/article/details/14184097
RHEL官網資料：
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