Linux 磁盘管理

 

一、实验环境

1、VMware WorkStation虚拟机安装操作系统：Red Hat Enterprice Linux 5.5；

2、磁盘：除Linux系统磁盘外，挂载3块大小为1G，一块大小为2G（做LVM实验时使用），类型为SCSI的磁盘；

二、实验目标

1、了解各种磁盘阵列的的优缺点与应用环境，以及Linux下软件配置RAID的方法；

2、实现Linux下LVM（逻辑卷管理）对RAID组成的逻辑磁盘配置与应用；

3、应用Linux提供的“磁盘配额（Disk Quota）”子系统管理逻辑卷。

三、实验内容

（一）、配置软件RAID

1、检查raid工具mdadm

1-1、检查系统是否已安装mdadm工具包

[root@localhost ~]# rpm -q mdadm

mdadm-2.6.9-3.el5

1-2、如果没有安装，手动安装mdadm-2.6.9-3.el5.rpm这个包。

2、准备实验磁盘

2-1、查看磁盘：

[root@localhost ~]# fdisk -l

Disk /dev/sda: 12.8 GB, 12884901888 bytes

255 heads, 63 sectors/track, 1566 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1        1402    11261533+  83  Linux

/dev/sda2            1403        1566     1317330   82  Linux swap / Solaris

Disk /dev/sdb: 1073 MB, 1073741824 bytes

255 heads, 63 sectors/track, 130 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/sdc: 1073 MB, 1073741824 bytes

255 heads, 63 sectors/track, 130 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdc doesn't contain a valid partition table

Disk /dev/sdd: 1073 MB, 1073741824 bytes

255 heads, 63 sectors/track, 130 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdd doesn't contain a valid partition table

2-2、对磁盘/dev/sdb进行分区：

[root@localhost ~]# fdisk /dev/sdb

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel

Building a new DOS disklabel. Changes will remain in memory only,

until you decide to write them. After that, of course, the previous

content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): n              #新建分区；

Command action

e   extended

p   primary partition (1-4)

p                                 #分区类型为主分区；

Partition number (1-4): 1              #第一个分区；

First cylinder (1-130, default 1):

Using default value 1

Last cylinder or +size or +sizeM or +sizeK (1-130, default 130):

Using default value 130                #使用全部空间（分一个区），以上两项直接回车；

Command (m for help): t               #选择分区格式；

Selected partition 1

Hex code (type L to list codes): fd        #选择分区格式为fd；

Changed system type of partition 1 to fd (Linux raid autodetect)

Command (m for help): w             #保存并退出。

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

2-3、磁盘/dev/sdc和/dev/sdd的分区方法与上面步骤一致。完成后，查看全部分区。

[root@localhost ~]# fdisk -l

Disk /dev/sda: 12.8 GB, 12884901888 bytes

255 heads, 63 sectors/track, 1566 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1        1402    11261533+  83  Linux

/dev/sda2            1403        1566     1317330   82  Linux swap / Solaris

Disk /dev/sdb: 1073 MB, 1073741824 bytes

255 heads, 63 sectors/track, 130 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1         130     1044193+  fd  Linux raid autodetect

Disk /dev/sdc: 1073 MB, 1073741824 bytes

255 heads, 63 sectors/track, 130 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1         130     1044193+  fd  Linux raid autodetect

Disk /dev/sdd: 1073 MB, 1073741824 bytes

255 heads, 63 sectors/track, 130 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sdd1               1         130     1044193+  fd  Linux raid autodetect

3、创建磁盘阵列

3-1、创建磁盘阵列RAID0

[root@localhost ~]# mdadm --create --verbose /dev/md0 --level=0 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1

mdadm: chunk size defaults to 64K

mdadm: array /dev/md0 started.

3-1-1、可以简写为[root@localhost ~]# mdadm -Cv /dev/md0 -l0 -n3 /dev/sd{b,c,d}1

3-1-2、还可以增加-c128参数，指定chunk size为128K（默认64K）

3-2、RAID1、RAID5创建过程和上面的方法相同。

4、mdadm的配置文件：mdadm不采用/etc/mdadm.conf作为主要配置文件，它可以完全不依赖该文件而不会影响阵列的正常工作。该配置文件的主要作用是方便跟踪软RAID的配置。对该配置文件进行配置是有好处的，但不是必须的。推荐对该文件进行配置。

4-1、格式：
        DEVICE 参与阵列的设备
        ARRAY 阵列的描述

4-2、创建mdadm.conf 配置文件

[root@localhost ~]# mdadm --detail --scan >> /etc/mdadm.conf

[root@localhost ~]# vi /etc/mdadm.conf

[root@localhost ~]# cat /etc/mdadm.conf

DEVICE /dev/sdb1 /dev/sdc1 /dev/sdd1

ARRAY /dev/md0 level=raid0 num-devices=3 metadata=0.90 UUID=75e92985:cb128e1d:a99bce53:46f65900

5、格式化磁盘阵列

5-1、格式化磁盘阵列 /dev/md0

[root@localhost ~]# mkfs.ext3 /dev/md0

mke2fs 1.39 (29-May-2006)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

391680 inodes, 783072 blocks

39153 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=805306368

24 block groups

32768 blocks per group, 32768 fragments per group

16320 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912

Writing inode tables: done

Creating journal (16384 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 22 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.