提示两点：
*新加的硬盘需要重启服务器fdisk -l才能看到
*下面操作要用root账户
大概是这样的，查看-分区-格式化-挂载-重启自动挂载
1、加硬盘后重启服务器查看
[root@test199 ~]# fdisk -l

Disk /dev/sdb: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

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

Disk /dev/sda: 85.9 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000cd039

Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 536 4096000 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 536 10444 79584256 83 Linux
2、分区
fdisk可以用m命令来看fdisk命令的内部命令；
a：命令指定启动分区；
d：命令删除一个存在的分区；
l：命令显示分区ID号的列表；
m：查看fdisk命令帮助；
n：命令创建一个新分区；
p：命令显示分区列表；
t：命令修改分区的类型ID号；
w：命令是将对分区表的修改存盘让它发生作用。

[root@test199 ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x515ae162.
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)

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').

Command (m for help): n
Command action
e extended //输入e为创建扩展分区
p primary partition (1-4) //输入p为创建逻辑分区
p
Partition number (1-4): 1 //在这里输入l，就进入划分逻辑分区阶段了
First cylinder (1-26108, default 1): //注：这个就是分区的Start 值；这里最好直接按回车，如果您输入了一个非默认的数字，会造成空间浪费；
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-26108, default 26108): 我这直接回车了全部用上。注：这个是定义分区大小的，+200M 就是大小为200M ；当然您也可以根据p提示的单位cylinder的大小来算，然后来指定 End的数值。回头看看是怎么算的；还是用+200M这个办法来添加，这样能直观一点。如果您想添加一个10G左右大小的分区，请输入 +10000M ；
Using default value 26108

Command (m for help): w //最后输入w回车保存。
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
保存后查看一下
[root@test199 ~]# fdisk -l

Disk /dev/sdb: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x515ae162

Device Boot Start End Blocks Id System
/dev/sdb1 1 26108 209712478+ 83 Linux

Disk /dev/sda: 85.9 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000cd039

Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 536 4096000 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 536 10444 79584256 83 Linux
3、格式化
[root@test199 ~]# mkfs.ext3 /dev/sdb1 //注：将/dev/sdb1格式化为ext3类型，确认好，我上面/dev/sdb1是新加的200GB硬盘，这一步直接回车就可以了，格式化完会自动跳出来
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
13107200 inodes, 52428119 blocks
2621405 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
1600 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
4、挂载
--先创建个目录、再挂载到目录上
[root@test199 ~]# mkdir /data
[root@test199 ~]# mount /dev/sdb1 /data
[root@test199 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 75G 21G 51G 29% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/sda1 194M 25M 160M 14% /boot
/dev/sdb1 197G 188M 187G 1% /data
5、重启开机自动挂载，要写到fstab里面(就是最后一行了)，否则重启后找不到那个新家的硬盘了
[root@test199 ~]# vi /etc/fstab
#
# /etc/fstab
# Created by anaconda on Tue Apr 16 01:33:57 2013
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=f87d8e1f-9a62-4cb8-93a8-a4793465eb23 / ext4 defaults 1 1
UUID=cdb27acf-3bbb-4f03-b20c-cfbc9d8450b9 /boot ext4 defaults 1 2
UUID=63399012-86b0-43e7-8cee-a0ace153dd7e swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/sdb1 /data ext3 defaults 0 0
至此OK！