fdisk 分區

1.1 fdisk 磁盤分區工具
受mbr分區表限制,只能給小於2T的磁盤劃分分區，
語法：
[fdisk] [option] [device]
參數：
-l 顯示全部磁盤分區的信息
1.1 交互式分區實踐

[root@lvs ~]# ls /dev/sd* 
[root@lvs ~]# fdisk /dev/sdb
Command (m for help): m
Command action
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
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').
     -c  提示使用-c關閉dos兼容模式
     -u 提示-u 參數使用扇區爲單位分區
Command (m for help): m    m  是幫助 
Command action
   a   toggle a bootable flag       #設置引導分區
   b   edit bsd disklabel               #編輯bsd分區
   c   toggle the dos compatibility flag    #設置dos兼容扇區
   d   delete a partition                                  # 刪除一個分區
   l   list known partition types            #查看分區類型對應編號列表
   m   print this menu                         # 打印幫助菜單
   n   add a new partition                    #新建一個分區
   o   create a new empty DOS partition table   #建立一個新的dos分區表
   p   print the partition table                #打印分區表
   q   quit without saving changes         #退出不保存更改
   s   create a new empty Sun disklabel    #建立新的sun卷標
   t   change a partition's system id            #更改分區系統id
   u   change display/entry units               #改變顯示/條目的單位
   v   verify the partition table               #驗證分區表
   w   write table to disk and exit          #將操做寫入分區表並退出程序
   x   extra functionality (experts only)    #額外的功能
Command (m for help): n    #新創建一個分區
Command action
   e   extended    擴展分區
   p   primary partition (1-4)    建立主分區
p    建立一個主分區，須要人工輸入p後回車
Partition number (1-4): 1  設置主分區編號1 
First cylinder (1-261083, default 1): 1G   設置柱起面,默認爲1
Last cylinder, +cylinders or +size{K,M,G} (1-261083, default 261083): 100G    #設置結束柱面
Command (m for help): p  打印分過的分區表

Disk /dev/sdb: 2147.5 GB, 2147483648000 bytes
255 heads, 63 sectors/track, 261083 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: 0xc4682775

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1         100      803218+  83  Linux
Command (m for help): n  再創建一個分區表
Command action
   e   extended
   p   primary partition (1-4)
e   建立一個擴展分區
Partition number (1-4): 2   設置分區編號爲2
First cylinder (101-261083, default 101):   
Using default value 101
Last cylinder, +cylinders or +size{K,M,G} (101-261083, default 261083): 
Using default value 261083
Command (m for help): p

Disk /dev/sdb: 2147.5 GB, 2147483648000 bytes
255 heads, 63 sectors/track, 261083 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: 0xc4682775

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1         100      803218+  83  Linux
/dev/sdb2             101      261083  2096345947+   5  Extended
Command (m for help): n  再創建一個分區
Command action   
   l   logical (5 or over)   分了擴展分區,這裏自動變爲邏輯分區
   p   primary partition (1-4)
p
Partition number (1-4): 3
No free sectors available   不能再建立主分區,沒有磁盤空間了
Command (m for help): n   再新建一個分區
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l   新創建一個邏輯分區
First cylinder (101-261083, default 101): 
Using default value 101
Last cylinder, +cylinders or +size{K,M,G} (101-261083, default 261083): 400G

Command (m for help): p  打印分區表

Disk /dev/sdb: 2147.5 GB, 2147483648000 bytes
255 heads, 63 sectors/track, 261083 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: 0xc4682775

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1         100      803218+  83  Linux
/dev/sdb2             101      261083  2096345947+   5  Extended
/dev/sdb5             101         400     2409718+  83  Linux

Command (m for help): n  新創建一個分區
Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l     新創建一個邏輯分區
First cylinder (401-261083, default 401): 401
Last cylinder, +cylinders or +size{K,M,G} (401-261083, default 261083): 
Using default value 261083

Command (m for help): p

Disk /dev/sdb: 2147.5 GB, 2147483648000 bytes
255 heads, 63 sectors/track, 261083 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: 0xc4682775

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1         100      803218+  83  Linux
/dev/sdb2             101      261083  2096345947+   5  Extended
/dev/sdb5             101         400     2409718+  83  Linux
/dev/sdb6             401      261083  2093936166   83  Linux

Command (m for help): w   將操做寫入分區表生效並退出
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
[root@lvs ~]# ls /dev/sd*  查看分區後的狀態
/dev/sda  /dev/sda1  /dev/sda2  /dev/sda3  /dev/sdb  /dev/sdb1  /dev/sdb2  /dev/sdb5  /dev/sdb6  /dev/sdc
[root@lvs ~]# partprobe /dev/sdb  執行該命令通知內核分區表已經更改,此部是不重啓讓分區表生效的命令
[root@lvs ~]# 
  1.2格式化磁盤

[root@lvs ~]# mkfs.ext4 /dev/sdb1
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
50288 inodes, 200804 blocks
10040 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=209715200
7 block groups
32768 blocks per group, 32768 fragments per group
7184 inodes per group
Superblock backups stored on blocks: 
    32768, 98304, 163840

Writing inode tables: done                            
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 31 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.   執行這個命令能夠避免磁盤掛自動檢查磁盤。
  1.3掛載磁盤分區
[root@lvs ~]# df -h  顯示磁盤使用的狀況
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2        79G  3.4G   71G   5% /
tmpfs           491M     0  491M   0% /dev/shm
/dev/sda1       194M   29M  155M  16% /boot
[root@lvs ~]# mount /dev/sdb1 /mnt磁盤只能掛了才能使用,將磁盤掛載到/mnt下

[root@lvs ~]# df -h 
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2        79G  3.4G   71G   5% /
tmpfs           491M     0  491M   0% /dev/shm
/dev/sda1       194M   29M  155M  16% /boot
/dev/sdb1       773M   17M  717M   3% /mnt
[root@lvs ~]# vim /etc/fstab
/dev/sdb1               /mnt                    ext4    defaults        0 0

在用交互指令d刪除分區時要當心,看好分區的序號,若是刪除了擴展分區，那麼擴展分區之下的邏輯分區都會被刪除,所在在操做時要當心,若是不當心刪除錯誤,按q退出,這樣以前的操做就會失效,若是輸入(w保存指令)則會保存全部修改