Linux系統由于數據累計增長、前期存儲規劃不合理等諸多因素，出現存儲不夠用的情況時，此時就需要擴展邏輯分區或添加新的邏輯分區。下面介紹一下通過使用fdsik添加新的邏輯分區。

首先使用df命令檢查文件系統的磁盤空間占用情況

[root@DB-ONE-SERVER~]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup00-sda3

                       30G  2.4G   26G   9% /

/dev/sda1              99M   23M   71M  25% /boot

tmpfs                 4.0G     0  4.0G   0% /dev/shm

You have new mail in /var/spool/mail/root

然后使用fdisk -l查看分區表信息

[root@DB-ONE-SERVER~]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 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        5221    41833260   8e  Linux LVM

Disk /dev/sdb: 21.4 GB, 21474836480 bytes

255 heads, 63 sectors/track, 2610 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

Disk /dev/dm-0: 32.3 GB, 32346472448 bytes

255 heads, 63 sectors/track, 3932 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-0 doesn't contain a valid partition table

Disk /dev/dm-1: 10.4 GB, 10468982784 bytes

255 heads, 63 sectors/track, 1272 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-1 doesn't contain a valid partition table

fdisk命令參數介紹

p、打印分區表。

n、新建一個新分區。

d、刪除一個分區。

m、輸出菜單

q、退出不保存。

w、把分區寫進分區表，保存并退出。

[root@DB-ONE-SERVER~]# 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.

The number of cylinders for this disk is set to 2610.

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)

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

Command (m for help): m

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