1、Linux Raid安装过程详解Linux Raid安装过程详解操作环境为64bit CentOS6.0 同样适用于redhat其他内核版本此文以raid1为例 raid0,5,6配置过程类似文章完全亲自操作，属原创，如有不足欢迎指正 HONKER_NEMO微博地址：微刊地址：首先查看当前系统分区情况rootlocalhost # fdisk -l|grep sdDisk /dev/sda: 32.2 GB, 32212254720 bytes/dev/sda1 * 1 64 512000 83 Linux/dev/sda2 64 3917 30944256 8e Linux LVMDisk
2、/dev/sdb: 3221 MB, 3221225472 bytes可以看到当前系统有一块3G左右的硬盘未分区使用，将其分区用作raid磁盘，分为3个主分区与1个扩展分区rootlocalhost # fdisk /dev/sdbWARNING: DOS-compatible mode is deprecated. Its strongly recommended to switch off the mode (command c) and change display units to sectors (command u).Command (m for help): nCommand a
3、ction e extended p primary partition (1-4)pPartition number (1-4): 1First cylinder (1-391, default 1):Using default value 1Last cylinder, +cylinders or +sizeK,M,G (1-391, default 391): +200MCommand (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4):Value out of
4、 range.Partition number (1-4): 2First cylinder (27-391, default 27):Using default value 27Last cylinder, +cylinders or +sizeK,M,G (27-391, default 391): +200MCommand (m for help): nCommand action e extended p primary partition (1-4)pPartition number (1-4): 3First cylinder (53-391, default 53):Using
5、default value 53Last cylinder, +cylinders or +sizeK,M,G (53-391, default 391): +200MCommand (m for help): nCommand action e extended p primary partition (1-4)eSelected partition 4First cylinder (79-391, default 79):Using default value 79Last cylinder, +cylinders or +sizeK,M,G (79-391, default 391):U
6、sing default value 391Command (m for help): pDisk /dev/sdb: 3221 MB, 3221225472 bytes255 heads, 63 sectors/track, 391 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x7429
7、a3f1 Device Boot Start End Blocks Id System/dev/sdb1 1 26 208813+ 83 Linux/dev/sdb2 27 52 208845 83 Linux/dev/sdb3 53 78 208845 83 Linux/dev/sdb4 79 391 2514172+ 5 Extended至此已经分好了三个主分区与一个扩展分区sdb14 其中计划使用sdb1与sdb2作为raid分区所以要将raid1与raid2的标识更改为raid标识Command (m for help): tPartition number (1-5): 1l显示所有
8、的标识对应的含义，raid磁盘对应的标识为fdHex code (type L to list codes): l0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris 1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-4 FAT16 32M 41 PPC
9、 PReP Boot 85 Linux extended c7 Syrinx 5 Extended 42 SFS 86 NTFS volume set da Non-FS data 6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility 8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt 9 AIX bootable 50 OnTrack DM 93 Amoeba e
10、1 DOS access a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT f W95 Extd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/10 OPUS
11、 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor 12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor 14 Hidden FAT16 3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary 16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS 17 Hidden
12、HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep 1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT 1e Hidden W95 FAT1Hex code (type L to list codes): fdChanged sys
13、tem type of partition 1 to fd (Linux raid autodetect)Command (m for help): tPartition number (1-5): 2Hex code (type L to list codes): fdChanged system type of partition 2 to fd (Linux raid autodetect)Command (m for help): pDisk /dev/sdb: 3221 MB, 3221225472 bytes255 heads, 63 sectors/track, 391 cyli
14、ndersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x7429a3f1 Device Boot Start End Blocks Id System/dev/sdb1 1 26 208813+ fd Linux raid autodetect/dev/sdb2 27 52 208845 fd Linux
15、raid autodetect/dev/sdb3 53 78 208845 83 Linux/dev/sdb4 79 391 2514172+ 5 Extended更改好标识后，输入w按回车保存并退出Command (m for help): wThe partition table has been altered!Calling ioctl() to re-read partition table.Syncing disks.再次查看当前系统分区，发现sdb由原先的未使用状态变成了4个分区rootlocalhost # fdisk -l|grep sdDisk /dev/sda: 32.2
16、 GB, 32212254720 bytes/dev/sda1 * 1 64 512000 83 Linux/dev/sda2 64 3917 30944256 8e Linux LVMDisk /dev/sdb: 3221 MB, 3221225472 bytes/dev/sdb1 1 26 208813+ fd Linux raid autodetect/dev/sdb2 27 52 208845 fd Linux raid autodetect/dev/sdb3 53 78 208845 83 Linux/dev/sdb4 79 391 2514172+ 5 Extended现在开始创建
17、raid磁盘组，使用mdadm命令 -C指定raid名称 -l指定raid级别，这里以raid1为例 -n指定设备的数量，这里有两个设备，sdb1与sdb2rootlocalhost # mdadm -C /dev/md0 -l 1 -n 2 /de/sdb1/ /dev/sdb2mdadm: cannot open /dev/sdb1: Device or resource busy报错信息显示资源使用中无法访问查看md0信息发现此时已有一个md0的设备在使用sd1与sd2分区，是由于上次安装raid卸载不完全造成的rootlocalhost #mdadm -detail /dev/md0/
18、dev/md0: Version : 1.2Creation Time : Sat Nov 10 01:05:44 2012 Raid Level : raid1 Array Size : 208801 (203.94 MiB 213.81 MB)Used Dev Size : 208801 (203.94 MiB 213.81 MB) Raid Devices : 2Total Devices : 2 Persistence : Superblock is persistent Update Time : Sat Nov 10 01:05:46 2012 State : cleanActiv
19、e Devices : 2Working Devices : 2Failed Devices : 0Spare Devices : 0 Name : localhost.localdomain:0 (local to host localhost.localdomain) UUID : 5984d686:d1f3ed71:55d427f3:4803a8ce Events : 17 Number Major Minor RaidDevice State 0 8 17 0 active sync /dev/sdb1 1 8 18 1 active sync /dev/sdb2找到问题后，使用mda
20、dm -S命令终止md0占用sd1与sd2rootlocalhost # mdadm -S /dev/md0mdadm: stopped /dev/md0再次查看md0信息，确认终止成功rootlocalhost # mdadm -detail /dev/md0mdadm: cannot open /dev/md0: No such file or directory重复之前创建raid的命令rootlocalhost # mdadm -C /dev/md0 -l 1 -n 2 /de/sdb1/ /dev/sdb2mdadm: /dev/sdb1 appears to contain an
21、ext2fs file system size=208812K mtime=Thu Jan 1 08:00:00 1970mdadm: /dev/sdb1 appears to be part of a raid array: level=raid1 devices=2 ctime=Sat Nov 10 01:05:44 2012mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store /boot on this device
22、please ensure that your boot-loader understands md/v1.x metadata, or use -metadata=0.90mdadm: /dev/sdb2 appears to contain an ext2fs file system size=208844K mtime=Thu Jan 1 08:00:00 1970mdadm: /dev/sdb2 appears to be part of a raid array: level=raid1 devices=2 ctime=Sat Nov 10 01:05:44 2012Continue
23、 creating array? y 这里输入y 回车mdadm: Defaulting to version 1.2 metadatamdadm: array /dev/md0 started.进入/dev目录下，ls 发现新增了一个md0设备，该设备即为之前刚刚创建的raid设备rootlocalhost dev# ls m*0m40;33;01mmcelog0m 40;33;01mmd00m 40;33;01mmem0m 40;33;01mmidi0mmapper:40;33;01mcontrol0m 01;36mVolGroup-lv_root0m 01;36mVolGroup-lv_
24、swap0mmd:md-device-map创建好raid后给raid设备进行ext4格式格式化rootlocalhost dev# mkfs.ext4 /dev/md0mke2fs 1.41.12 (17-May-2010)Filesystem label=OS type: LinuxBlock size=1024 (log=0)Fragment size=1024 (log=0)Stride=0 blocks, Stripe width=0 blocks52208 inodes, 208800 blocks10440 blocks (5.00%) reserved for the supe
25、r userFirst data block=1Maximum filesystem blocks=6737100826 block groups8192 blocks per group, 8192 fragments per group2008 inodes per groupSuperblock backups stored on blocks:8193, 24577, 40961, 57345, 73729, 204801Writing inode tables: 0/26 1/26 2/26 3/26 4/26 5/26 6/26 7/26 8/26 9/2610/2611/2612
26、/2613/2614/2615/2616/2617/2618/2619/2620/2621/2622/2623/2624/2625/26done Creating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: doneThis filesystem will be automatically checked every 30 mounts or180 days, whichever comes first. Use tune2fs -c or -i to override.格式化完成之后，进入空目录/mnt/，找到已经创建好的空目录raid/准备将其作为md0设备的mount点rootlocalhost dev# cd /mnt/rootlocalhost mnt# ls0m01;34mhgfs0m 01;34mraid0mrootlocalhost mnt# cd raid/rootlocalhost raid# ls挂载raid设备md0到/mnt/raid空目录下rootlocalhost raid# mount /dev/md0 /mnt/raid/查看当前系统分区与挂载点 显示挂载成功rootlocalhost raid# dfFilesyste
