LINUX 制作 RAID5卷和LVM逻辑卷
环境搭建
虚拟机装有linux操作系统.
在windows物理机上有SecurCRT或者putty等和linux操作系统远程连接的软件。
首先查看linux的ip地址，连接SecurCRT输入linux上的ip地址、root用户名和密码来进行远程连接
如下图
安装mdadm软件包
创建RAID卷需要用的命令mdadm,就要先安装好mdadm软件包
创建挂载点/mnt/cdrom/
使用mount将光盘挂载到/mnt/cdrom/目录下，进入目录/mnt/cdrom/Packages/
查看mdadm安装包
[root@localhost ~]# mkdir /mnt/cdrom
[root@localhost ~]# mount /dev/cdrom /mnt/cdrom
mount: /dev/sr0 is write-protected,mounting read-only
[root@localhost ~]# cd /mnt/cdrom
[root@localhost cdrom]# cd Packages/
[root@localhost Packages]# ls mdadm*
mdadm-3.2.6-31.el7.x86_64.rpm
使用rpm或者yum来安装
[root@localhostPackages]# rpm -Uvhmdadm-3.2.6-31.el7.x86_64.rpm
warning:mdadm-3.2.6-31.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5:NOKEY
Preparing... ################################# [100%]
package mdadm-3.2.6-31.el7.x86_64 isalready installed
RAID5卷
使用命令fdisk –l来查看硬盘情况
[root@localhost ~]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes,83886080 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
Disk label type: dos
Disk identifier: 0x000ca5cb
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 83886079 41430016 8e Linux LVM
Disk /dev/mapper/centos-swap: 1107 MB,1107296256 bytes, 2162688 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
Disk /dev/mapper/centos-root: 41.3 GB,41313894400 bytes, 80691200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
添加硬盘
增加3块硬盘，因为构建RAID5卷至少需要3块硬盘
为了方面分辨，我给3块硬盘分别分为20GB 、21GB、22GB
方法一 ：使用reboot命令重启，LINUX才能识别到新添加的3块硬盘
[root@localhost ~]# reboot
方法二 ：使用命令对linux系统的磁盘进行扫描，就能识别到新添加的3块硬盘
[root@localhost ~]# echo "- - -" > /sys/class/scsi_host/host0/scan
[root@localhost ~]# echo "- - -" > /sys/class/scsi_host/host1/scan
[root@localhost ~]# echo "- - -" > /sys/class/scsi_host/host2/scan
再用fdisk –l查看系统中的所有磁盘信息，就发现有3块新添加的磁盘，没有分区。
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Disk /dev/sdb: 21.5 GB, 21474836480 bytes,41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
Disk /dev/sdc: 22.5 GB, 22548578304 bytes,44040192 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
Disk /dev/sdd: 23.6 GB, 23622320128 bytes,46137344 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
创建分区
创建分区，分别将新添加的每块硬盘都规划一个分区
首先进入/dev/sdb/
[root@localhost ~]# fdisk /dev/sdb
使用字母l可以查看更改分区类型
Command (m for help): l
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx
5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data
6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility
8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
1e Hidden W95 FAT1 80 Old Minix
将分区更改为fd（RAID卷），不是RAID5卷，RAID卷有几种类型。这里并没有格式化硬盘。
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linuxraid autodetect'
Command (m for help): p 查看
Disk /dev/sdb: 21.5 GB, 21474836480 bytes,41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes /512 bytes
I/O size (minimum/optimal): 512 bytes / 512bytes
Disk label type: dos
Disk identifier: 0xd6c74515
Device Boot Start End Blocks Id System
/dev/sdb1 2048 41943039 20970496 fd Linux raid autodetect
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
分别规划、/dev/sdc/ /dev/sdd/
步骤同/dev/sdb/一样
创建RAID5卷
-C， -----create：指的是创建一个新的阵列
-l ，level= : 设定raid level 这里为RAID5
-n , 指定阵列中可用device数目，这里为3，表示3块硬盘
Sd[bcd]1, 整个意思为sdb1 , sdc1,sdd1 表示3个分区
使用命令创建RAID5
[root@localhost ~]# mdadm -C /dev/md5 -l5 -n3 /dev/sd[bcd]1
mdadm: largest drive (/dev/sdd1) exceedssize (20953600K) by more than 1%
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm:array /dev/md5 started
创建PV物理卷，将/dev/md5转化成物理卷
[root@localhost ~]# pvcreate /dev/md5
Physicalvolume "/dev/md5" successfully created
创建VG卷组，将/dev/md5创建为卷组，名字为mail_stor
[root@localhost~]# vgcreate mail_ste/dev/md5
^H Volume group "mail_ste"successfully created
[root@localhost~]# vgdisplay
--- Volume group ---
VG Name mail_ste
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 39.96 GiB
PE Size 4.00 MiB
Total PE 10231
Alloc PE / Size 0 / 0
Free PE / Size 10231 / 39.96 GiB
VG UUID 6vCcS8-Hsm8-eet4-WKZ6-qw2b-0bIB-FmRWB3
LVM卷
创建LV逻辑卷，在卷组mail_ste中创建一个名为mail的逻辑卷，容量大小为39GB
注意这里的容量大小不能有小数点，所以只能提取39GB
[root@localhost ~]# lvcreate -L 39G -n mail mail_ste
Logical volume "mail" created
格式化mail的逻辑卷，文件系统为ext4
[root@localhost ~]# mkfs -t ext4/dev/mail_ste/mail
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=128 blocks, Stripe width=256 blocks
2555904 inodes, 10223616 blocks
511180 blocks (5.00%) reserved for thesuper user
First data block=0
Maximum filesystem blocks=2157969408
312 block groups
32768 blocks per group, 32768 fragments pergroup
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystemaccounting information: done
最后在根目录下创建目录RAID5
将逻辑卷挂载到/raid5下
[root@localhost ~]# mkdir /raid5
[root@localhost ~]# mount/dev/mail_ste/mail /raid5
查看硬盘使用情况，可以看到/raid5
[root@localhost ~]#df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 39G 986M 38G 3% /
devtmpfs devtmpfs 236M 0 236M 0% /dev
tmpfs tmpfs 242M 0 242M 0% /dev/shm
tmpfs tmpfs 242M 4.5M 238M 2% /run
tmpfs tmpfs 242M 0 242M 0% /sys/fs/cgroup
/dev/sda1 xfs 497M 98M 400M 20% /boot
/dev/sr0 iso9660 3.9G 3.9G 0 100% /mnt/cdrom
/dev/mapper/mail_ste-mail ext4 39G 49M 37G 1% /raid5
编辑系统挂载目录的配置文件，开启自动挂载
[root@localhost ~]# vi /etc/fstab
在最后一行添加
测试
在/raid5下创建目录aa，再次查看，创建成功，说明RAID5卷是好的
[root@localhost ~]# cd /raid5
[root@localhost raid5]# mkdir aa
[root@localhost raid5]# ll
total 20
drwxr-xr-x 2 root root 4096 Aug 20 12:03 aa
drwx------ 2 root root 16384 Aug 20 11:50 lost+found