centos上iscsi+multipath多路径存储配置手册

centosiscsi+multipath名目一：客户端安装iscsi包。二：zai共享存储上为效劳器划分磁盘空间。iscsidm-multipath包。五：配置参数修改和测试。iscsi安装包。1iscsiinitiator包。安装包从安装光盘中找到root@bhnfs1.baihui~>rpm-qa|grepiscsiiscsi-initiator-utils-6.2.0.868-0.7.el52、在/etc/iscsi/名目下/etc/iscsi/initiatorname.iscsiiqnEVAcommandviewHOST时需用到。二:为效劳器划分磁盘阵列的磁盘空间〔Virtualdisk〕具体详见存储配置。ISCSI1ISCSI效劳：root@bhnfs1.baihui~>serviceiscsistart2ISCSI设备〔HPstorageworksmpx100〕targetiqn号码：〔必需〕root@bhnfs1.baihui~>iscsiadm-mdiscovery-tsendtargets-p192.168.14.1192.168.14.1:3260,0iqn.1986-03.hp:fcgw.mpx100.0.50014380025bad30.50014380025bad383ISCSI存储设备[root@localhost~]#Iscsiadm–mnode–Tiqn.1986-03.hp:fcgw.mpx100.0.50014380025bad30.50014380025bad38-p192.168.14.1:3260–l上面命令是连续的，其中iqn号码为上面查询得到的号码，ip为iscsi存储中iscsi口对外映射的地址。4、查看磁盘:[root@localhost~]#fdisk-lDisk/dev/sda:8795MB,8795105280bytes255heads,63sectors/track,1069cylindersUnits=cylindersof16065*512=8225280bytesDeviceBootStartEndBlocksIdSystem/dev/sda1*1941755855183Linux/dev/sda294210681020227+82Linuxswap/SolarisDisk/dev/sdb:10.4GB,10487232022bytes255heads,63sectors/track,1275cylindersUnits=cylindersof16065*512=8225280bytesDeviceBootStartEndBlocksIdSystem得到的盘符5ISCSItarget。〔mpx100ISCSIiqnip地址〕添加成功后fdisk–l应当可以看到两个盘符。他们的容量都一样。这两个盘符对应的是同一LUN。6：映射完成之后使用下面命令查看映射结果：root@bhnfs1.baihui~>iscsiadm-mnode192.168.14.1:3260,0iqn.1986-03.hp:fcgw.mpx100.0.50014380025bad30.50014380025bad38192.168.14.3:3260,0iqn.1986-03.hp:fcgw.mpx100.0.50014380025bad30.50014380025bad3cDM-multipath软件包multipathcentos中已经安装好了。如没有执行下面的命令。〔原理为EVA4400中的一个真实的virtualdisk22个MPX100B对外供给映射，故效劳器上可以看到两个物理磁盘，但此磁盘对应一个真实的一个真实的virtualdisk，故这两条路径间可以实现故障切换和负载均衡〕rpmrpm–ivhdevice-mapper-1.02.13-6.9.i686.rpmrpm–ivhmultipath-tools-0.4.7-34.18.i686.rpm安装完成后，使用命令modprobedm_multipath来加载相应的模块，lsmod|grepdm_multipath来检查安装是否正常。六：配置文件的修改及创立1： multipath.conf文件，编辑的配置文件：实际有用的就是下面这些参数：其余参数都可以注释掉：defaults{user_friendly_namesyesudev_dir/devpath_grouping_policymultibusfailbackimmediateno_path_retryfail}保存退出2：启动效劳：Servicemultipathdrestart启动成功后，我们会在dev名目下看到下面的名目：/dev/mapper/mpathn,/dev/mpath/mpathn,/dev/dm-n./dev/mapper/mpathn/dev/mpath/mpathn这个是udev/dev/dm-n3：用multipathllA/A关系。断掉其中一根线路，那么系统自动切换到另外一条。root@bhnfs1.baihui~>multipath-llmpath2(3600508b4000a5bfd0000b00000202200)dm-2HP,HSV300[size=2.0T][features=0][hwhandler=0]\_round-robin0[prio=2][active]\_1:0:0:2sdd8:48[active][ready]\_2:0:0:2sdf8:80[active][ready]mpath1(3600508b4000a5bfd0000b000001a0000)dm-1HP,HSV300[size=2.0T][features=0][hwhandler=0]\_round-robin0[prio=2][active]\_1:0:0:1sdb8:16[active][ready]\_2:0:0:1sdc8:32[active][ready]mpath3(3600508b4000a5bfd0000b00000350000)dm-3HP,HSV300[size=2.0T][features=0][hwhandler=0]\_round-robin0[prio=2][active]\_1:0:0:3sde8:64[active][ready]\_2:0:0:3sdg8:96[active][ready]4：在多路径设备创立后，我们就可以像使用实际的物理设备样使用多路径设备了。前提是必需通过下面的命令将其标记为物理卷。pvcreate/dev/mapper/mpath15：然后对磁盘进展分区和格式化fdisk/dev/mapper/mpath1〔论〕dev/mapper/名目下创立的块设备，/dev/mapper/mpath1p1这个表示mpath11.multipath–Fmultipath–v3命令重加载。fdisk–ldm-1磁盘下面已经有分区的信息了。****************************************************isk/dev/dm-1:2197.9GB,2197949513728bytes255heads,63sectors/track,267218cylindersUnits=cylindersof16065*512=8225280bytesDeviceBootStartEndBlocksIdSystem/dev/dm-1p1112157797656722183Linuxmkfs.ext3/dev/mapper/mpath0p1****************************************************6mount7multipathd效劳设置成开机自启动chkconfigmultipathdon8：留意事项：iscsi连接：假设由于错误配置等缘由创立了iscsi对应，系统不会自动删除，需手动删除。例如：[root@as-h-01~]#iscsiadm-mnode192.168.1.51:3260,1iqn.2022-01.openfiler:tsn.59dc8fc04fa2我们看到上面有一个iscsi对应，但实际中这个对应已经失效，系统不会自动删除。删除命名：iscsiadm-mnode-odelete-Tiqn.2022-01.openfiler:tsn.59dc8fc04fa2-p192.168.1.51:3260假设其中一条链路消灭故障，那么在日志里面我们可以看到如下类似的信息：root@bhnfs1.baihui~>tail/var/log/messagesDec1214:03:15bhnfs1kernel:iscsi:cmd0x28isnotqueued(8)Dec1214:03:15bhnfs1kernel:iscsi:cmd0x28isnotqueued(8)Dec1214:03:15bhnfs1multipathd:sdf:readsector0checkerreportspathisdownDec1214:03:15bhnfs1multipathd:sdg:readsector0checkerreportspathisdownDec1214:03:20bhnfs1kernel:iscsi:cmd0x28isnotqueued(8)Dec1214:03:20bhnfs1multipathd:sdc:readsector0checkerreportspathisdownDec1214:03:20bhnfs1kernel:iscsi:cmd0x28isnotqueued(8)Dec1214:03:20bhnfs1multipathd:sdf:readsector0checkerreportspathisdownDec1214:03:20bhnfs1kernel:iscsi:cmd0x28isnotqueued(8)Dec1214:03:20bhnfs1multipathd:sdg:readsector0checkerreportspathisdownroot@bhnfs1.baihui/etc>multipath-llsdc:checkermsgis“readsector0checkerreportspathisdown“sdf:checkermsgis“readsector0checkerreportspathisdown“sdg:checkermsgis“readsector0checkerreportspathisdown“mpath2(3600508b4000a5bfd0000b00000202200)dm-2HP,HSV300[size=2.0T][features=0][hwhandler=0]\_round-robin0[prio=1][active]\_1:0:0:2sdd8:48[active][ready]\_2:0:0:2sdf8:80[failed][faulty]mpath1(3600508b4000a5bfd0000b000001a0000)dm-1HP,HSV300[size=2.0T][features=0][hwhandler=0]\_round-robin0[prio=