系统环境： CentOS 5.2
硬件配置： ASUS P5GC-MX +Intel E2160+Kinston 1GB 667*2+D-Link 530 1Gbps
硬盘 1 ： Seagate 80GB/7200S/8MB/SATA
硬盘 2 ： Seagate 1TB/7200S/32MB/SATA
硬盘 3 ： Seagate 1TB/7200S/32MB/SATA
场景：
笔者所在单位有一台用于备份文件的服务器目前空间不足（使用 Symantec Backup Exec 10d for Windows Servers 备份软件，备份文件服务器的所有数据，保留 15 天，每周六完整备份，周一至周五增量备份，现有 2TB 的空间已用完），该服务器已安装 8 个（容量与规格不一，有 SCSI/IDE/SATA ）硬盘，机箱内已无空间再增加硬盘，经过考虑，决定重新安装一台 LINUX 服务器配置 ISCSI 服务（提供 Target Server 角色），在 Windows Server 2003 上安装 Microsoft iSCSI Initiator 驱动，添加 ISCSI 硬盘，解决目前的空间问题；
目标：
Target Server 系统安装在 ST 80GB 的硬盘上，两块 1TB 的硬盘通过软件（ Software Raid ）配置为 Raid 0, 然后在 Raild 0 硬盘上配置 LVM ，在 LVM 上创建两个逻辑卷， LV1 （ data1 ）为 1.5TB ， LV2(data2) 为 325GB ；
Target server 建立两个 target device ，将 LVM 创建的两个逻辑卷分别加入两个 target device,node1 连接到 target device 1(iqn.2008-12.cn.lanexpert:iscsi-data1) ， node2 连接到 target device 2 （ iqn.2008-12.cn.lanexpert:iscsi-data2 ）
功能 操作系统 主机名称 IP地址 Iscsi-target server CentOS 5.2 Fsbak2.lanexpert.cn 192.168.3.19 Iscsi-initiator(node1) Windows Server 2003 Std R2 with sp2 Fsbak1.lanexpert.cn 192.168.3.18 Iscsi-initiator(node2) Windows XP Pro With sp3 Client1.lanexpert.cn 192.168.11.108
Target Server 系统安装在 Seagate 80GB 的硬盘上，在安装系统时，根据以下要求分区（仅为个人习惯，供参考），其它两个 1TB 的硬盘暂时不分区；
/boot 100MB
/ 10GB
/usr 20GB
/home 10GB
/var 30GB
Swap 3GB
系统选择最小化安装，仅安装最基本的服务；
一、 配置 Raid 0
#fdisk -l ( 显示所有连接在主机上的硬盘 )
Disk /dev/sda: 80.0 GB, 80025280000 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2624 20972857+ 83 Linux
/dev/sda3 2625 3929 10482412+ 83 Linux
/dev/sda4 3930 9729 46588500 5 Extended
/dev/sda5 3930 5234 10482381 83 Linux
/dev/sda6 5235 5708 3807373+ 82 Linux swap / Solaris
/dev/sda7 5709 9729 32298651 83 Linux
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
从以上信息可以看到， /dev/sda 连接的是我们的系统分区，其它两个硬盘（ sdb and sdc ）没有分区表；
现在，我们要为另外两个硬盘分别创建分区，参考如下：
#fdisk /dev/sdb
The number of cylinders for this disk is set to 121601.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
# 进入 fdisk 程序的工作画面后，如果硬盘太大，就会出现上述信息，这个信息表明，某些旧版本的软件与操作系统将无法支持大于 1024 柱面后的扇区使用
Command (m for help):m # 可以通过此命令查看所有参数
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): new
Command action
e extended
p primary partition (1-4) p
Partition number (1-4): 1
First cylinder (1-121601, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-121601, default 121601):
Using default value 121601
Command (m for help): type
Selected partition 1
Hex code (type L to list codes): fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): write
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
重复以上命令对 sdc 进行分区；
完毕后使用 fdisk –l 查看分区信息：
#fdisk -l
isk /dev/sda: 80.0 GB, 80025280000 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2624 20972857+ 83 Linux
/dev/sda3 2625 3929 10482412+ 83 Linux
/dev/sda4 3930 9729 46588500 5 Extended
/dev/sda5 3930 5234 10482381 83 Linux
/dev/sda6 5235 5708 3807373+ 82 Linux swap / Solaris
/dev/sda7 5709 9729 32298651 83 Linux
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 121601 976760001 fd Linux raid autodetect
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 121601 976760001 fd Linux raid autodetect
配置 raid 使用 mdadm 命令，有关该命令的具体参数参考 man mdadm;
# mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sdb1 /dev/sdc1
mdadm: array /dev/md0 started.
# cat /proc/mdstat # 查看 Raid 信息
Personalities : [raid0]
md0 : active raid0 sdc1[1] sdb1[0]
1953519872 blocks 64k chunks
unused devices: <none>
# fdisk -l
Disk /dev/sda: 80.0 GB, 80025280000 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2624 20972857+ 83 Linux
/dev/sda3 2625 3929 10482412+ 83 Linux
/dev/sda4 3930 9729 46588500 5 Extended
/dev/sda5 3930 5234 10482381 83 Linux
/dev/sda6 5235 5708 3807373+ 82 Linux swap / Solaris
/dev/sda7 5709 9729 32298651 83 Linux
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 121601 976760001 fd Linux raid autodetect
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 121601 976760001 fd Linux raid autodetect
Disk /dev/md0: 2000.4 GB, 2000404348928 bytes
2 heads, 4 sectors/track, 488379968 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk /dev/md0 doesn't contain a valid partition table
# mdadm --detail --scan
ARRAY /dev/md0 level=raid0 num-devices=2 UUID=bf5eb6f7:da2e7196:dc2b05b5:fa5903c1
为了让系统开机启动时自动加载 raid 信息，可以使用以下命令将配置信息写入 /etc/mdadm.conf 文件，该文件默认没有，可自行创建；
#echo DEVICE /dev/sdb1 /dev/sdc1 > /etc/mdadm.conf
#mdadm –detail –scan >> /etc/mdadm.conf (-- 为两个中短线 )
# cat /etc/mdadm.conf
DEVICE /dev/sdb1 /dev/sdc1
ARRAY /dev/md0 level=raid0 num-devices=2 UUID=bf5eb6f7:da2e7196:dc2b05b5:fa5903c1