Linux系统管理.Linux中软RAID的创建过程

Linux中raid的创建步骤：

1、添加硬盘

Raid设备的成员是硬盘分区，需要先对硬盘分区，分区不能同一个物理硬盘上

2、安装Raidtools工具

raidtools中包含有raid创建管理工具和默认的示范性配置文件

3、编写配置文件/etc/raidtab

可以从raidtools中的示范配置文件里复制后，再做修改处理

4、创建Raid设备

实例如下：

[root@localhost root]# fdisk -l

Disk /dev/sda: 5368 MB, 5368709120 bytes

255 heads, 63 sectors/track, 652 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/sda1 * 1 652 5237158+ 83 Linux

Disk /dev/sdb: 4294 MB, 4294967296 bytes

255 heads, 63 sectors/track, 522 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

Disk /dev/sdc: 4294 MB, 4294967296 bytes

255 heads, 63 sectors/track, 522 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

Command (m for help): n

Command action

e extended

p primary partition (1-4)

p

Partition number (1-4): 1

First cylinder (1-522, default 1):

Using default value 1

Last cylinder or +size or +sizeM or +sizeK (1-522, default 522):

Using default value 522

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

[root@localhost root]# fdisk /dev/sdc

Command (m for help): n

Command action

e extended

p primary partition (1-4)

p

Partition number (1-4): 1

First cylinder (1-522, default 1):

Using default value 1

Last cylinder or +size or +sizeM or +sizeK (1-522, default 522):

Using default value 522

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

[root@localhost root]# fdisk -l

Disk /dev/sda: 5368 MB, 5368709120 bytes

255 heads, 63 sectors/track, 652 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/sda1 * 1 652 5237158+ 83 Linux

Disk /dev/sdb: 4294 MB, 4294967296 bytes

255 heads, 63 sectors/track, 522 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/sdb1 1 522 4192933+ 83 Linux

Disk /dev/sdc: 4294 MB, 4294967296 bytes

255 heads, 63 sectors/track, 522 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

/dev/sdc1 1 522 4192933+ 83 Linux

[root@localhost root]# rpm -q raidtools

raidtools-1.00.3-2

[root@localhost root]# rpm -ql raidtools

/sbin/arytst

/sbin/detect_multipath

/sbin/lsraid

/sbin/mkraid

/sbin/raid0run

/sbin/raidhotadd

/sbin/raidhotremove

/sbin/raidreconf

/sbin/raidsetfaulty

/sbin/raidstart

/sbin/raidstop

/usr/share/doc/raidtools-1.00.3

/usr/share/doc/raidtools-1.00.3/COPYING

/usr/share/doc/raidtools-1.00.3/README

/usr/share/doc/raidtools-1.00.3/multipath.conf.sample

/usr/share/doc/raidtools-1.00.3/raid0.conf.sample

/usr/share/doc/raidtools-1.00.3/raid1.conf.sample

/usr/share/doc/raidtools-1.00.3/raid4.conf.sample

/usr/share/doc/raidtools-1.00.3/raid5.conf.sample

/usr/share/doc/raidtools-1.00.3/raidtab.sample

/usr/share/man

/usr/share/man/man5

/usr/share/man/man5/raidtab.5.gz

/usr/share/man/man8

/usr/share/man/man8/ckraid.8.gz

/usr/share/man/man8/lsraid.8.gz

/usr/share/man/man8/mkraid.8.gz

/usr/share/man/man8/raid0run.8.gz

/usr/share/man/man8/raidadd.8.gz

/usr/share/man/man8/raidreconf.8.gz

/usr/share/man/man8/raidrun.8.gz

/usr/share/man/man8/raidstart.8.gz

/usr/share/man/man8/raidstop.8.gz

[root@localhost root]# cp /usr/share/doc/raidtools-1.00.3/raid0.conf.sample /etc/raidtab

[root@localhost root]# vi /etc/raidtab

# Sample raid-0 configuration

raiddev /dev/md0

raid-level 0 # it’s not obvious but this *must* be

# right after raiddev

persistent-superblock 0 # set this to 1 if you want autostart,

# BUT SETTING TO 1 WILL DESTROY PREVIOUS

# CONTENTS if this is a RAID0 array created

# by older raidtools (0.40-0.51) or mdtools!

chunk-size 16

nr-raid-disks 2

nr-spare-disks 0

device /dev/hda1 <———修改此项为/dev/sdb1

raid-disk 0

device /dev/hdb1 <———修改此项为/dev/sdc1

raid-disk 1

[root@localhost root]# cat /etc/raidtab

# Sample raid-0 configuration

raiddev /dev/md0 <—–确认这一项

raid-level 0 # it’s not obvious but this *must* be

# right after raiddev

persistent-superblock 0 # set this to 1 if you want autostart,

# BUT SETTING TO 1 WILL DESTROY PREVIOUS

# CONTENTS if this is a RAID0 array created

# by older raidtools (0.40-0.51) or mdtools!

chunk-size 16

nr-raid-disks 2

nr-spare-disks 0

device /dev/sdb1 <—–确认这一项

raid-disk 0

device /dev/sdc1 <—–确认这一项

raid-disk 1

[root@localhost root]# mkraid /dev/md0

handling MD device /dev/md0

analyzing super-block

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

mke2fs 1.32 (09-Nov-2002)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

1048576 inodes, 2096464 blocks

104823 blocks (5.00%) reserved for the super user

First data block=0

64 block groups

32768 blocks per group, 32768 fragments per group

16384 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Writing inode tables: done

Creating journal (8192 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 21 mounts or

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

[root@localhost root]# mount /dev/md0 /opt

[root@localhost root]# mount

/dev/sda1 on / type ext3 (rw)

none on /proc type proc (rw)

usbdevfs on /proc/bus/usb type usbdevfs (rw)

none on /dev/pts type devpts (rw,gid=5,mode=620)

none on /dev/shm type tmpfs (rw)

/dev/md0 on /opt type ext3 (rw)

如果想始终使用raid 0 的话,那就做如下的操作:

[root@localhost root]# mkdir /mnt/raid0

[root@localhost root]# vi /etc/fstab

LABEL=/ / ext3 defaults 1 1

none /dev/pts devpts gid=5,mode=620 0 0

none /proc proc defaults 0 0

none /dev/shm tmpfs defaults 0 0

/dev/cdrom /mnt/cdrom udf,iso9660 noauto,owner,kudzu,ro 0 0

/dev/fd0 /mnt/floppy auto noauto,owner,kudzu 0 0

/dev/sdb5 /mnt/sdb5 ext3 defaults 0 0

/dev/md0 /mnt/raid0 ext3 defaults 0 0 <———–增加此行记录

如不想使用的话,可以先卸载raid目录,然后停止raid,最后删除/etc/raidtab文件,操作如下:

[root@localhost root]# mkdir /mnt/raid0

[root@localhost root]# umount /dev/md0

[root@localhost root]# raidstop /dev/md0

[root@localhost root]# rm /etc/raidtab

rm: remove regular file `/etc/raidtab’? y

完成所有的配置任务.

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