Fdisk 分區詳解
Fdisk 分區詳解
來源 http://blog.itpub.net/20674423/viewspace-722812/
1、 通過Fdisk查看系統分區詳細信息：
Fdisk –l 詳解：
[root@jetsenLin ~]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
註釋：這個硬盤的大小是10.7GB，有255個磁面，63個扇區，1305磁柱(cylinders)
每個 cylinder（磁柱）的容量是 8225280 bytes=8225.280 K（約為）=8.225280M（約為）；
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 1305 10377990 8e Linux LVM
id和System 表示的是一個意思，id看起來不太直觀，我們要在fdisk 一個分區時，通過指定id來確認分區類型；比如 7
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
說明： 硬盤分區的表示：在Linux 是通過hd*x 或 sd*x 表示的：
其中 * 表示的是a、b、c ... ...
另外 x 表示的數字 1
hd大多是IDE硬盤；sd大多是SCSI或移動存儲； 引導（Boot）：表示引導分區，在上面的例子中 sda1 是引導分區；
Start （開始）：表示的一個分區從X cylinder（磁柱）開始；
End （結束）：表示一個分區到 Y cylinder（磁柱）結束；
2、 學會使用fdisk幫助功能：
[root@jetsenLin ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 1305.
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)
Command (m for help): m ---輸出幫助信息
Command action
a toggle a bootable flag ---設置啟動分區
b edit bsd disklabel ---編輯分區標簽
c toggle the dos compatibility flag
d delete a partition --刪除一個分區
l list known partition types --列出分區類型
m print this menu --幫助
n add a new partition --建立一個新的分區
o create a new empty DOS partition table --創建一個新的空白DOS分區表
p print the partition table ---打印分區表
q quit without saving changes ---退出不保存設置
s create a new empty Sun disklabel ---
t change a partition‘s system id ---改變分區的ID
u change display/entry units ---改變顯示的單位
v verify the partition table ---檢查驗證分區表
w write table to disk and exit ---保存分區表
x extra functionality (experts only)
Command (m for help):
3、 通過Fdisk對磁盤分區進行操作：
Fdisk 創建分區：
[root@jetsenLin ~]# 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): n ---輸入m會有幫助信息出來，輸入n不打印幫助信息
Command action
e extended
p primary partition (1-4) ---指定分區類型 e為擴展分區 p為主分區
p
Partition number (1-4): 1 ---定義分區數量 --主分區最多只能有四個
First cylinder (1-2610, default 1): 1 ---設定起始分區的位置
Last cylinder or +size or +sizeM or +sizeK (1-2610, default 2610):
Using default value 2610 ---設定結束分區的位置
Command (m for help): w ---保存剛才的配置信息。
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@jetsenLin ~]#
Fdisk 刪除分區：
[root@jetsenLin ~]# fdisk /dev/sdb
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)
Command (m for help): d ---d 是代表刪除，並且會列出當前磁盤的分區數。
Selected partition 1
Command (m for help): p ----p 是代表刪除後，顯示磁盤還有幾個剩余的分區。
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System ----已經沒有分區了
Command (m for help): w ----保存剛才的操作並且生效
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
這裏報了一錯誤，分區表正在使用，刪除再下次啟動生效
Syncing disks. ---同步新的磁盤信息
[root@jetsenLin ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
通過fdisk 命令來創建一指定大小的分區並增加一個分區
Fdisk n
創建分區:
[root@jetsenLin ~]# fdisk /dev/sdb
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)
Command (m for help): n ---創建分區
Command action
e extended
p primary partition (1-4) --指定分區類型為主分區
p
Partition number (1-4): 1 --指定其實分區號
First cylinder (1-2610, default 1): 1 --指定起始柱面號
Last cylinder or +size or +sizeM or +sizeK (1-2610, default 2610): 1024 ---指定終止柱面號
Command (m for help): w ---保存分區配置信息
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
增加分區:
[root@jetsenLin ~]# fdisk /dev/sdb -----增加分區
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)
Command (m for help): n ---分區類型
Command action
e extended
p primary partition (1-4) ---還是指定主分區
p
Partition number (1-4): 1 ---分區號，我指定1。
Partition 1 is already defined. Delete it before re-adding it.
–提示分區號1已經存在，刪除後操作
Command (m for help): n --我們重新創建分區
Command action
e extended
p primary partition (1-4) --指定分區類型
p
Partition number (1-4): 2 ---因為分區1已經存在，所以我們指定分區2，可通過。
First cylinder (1025-2610, default 1025): ---指定起始礠柱號，默認是上一分區後一號。
Using default value 1025
Last cylinder or +size or +sizeM or +sizeK (1025-2610, default 2610): 2000 --指定終止礠柱號。
Command (m for help): w ---保存分區配置
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
[root@jetsenLin ~]#
通過fdisk 命令來來修改現有分區類型
Fdisk 通過t參數來指定
查看分區類型
[root@jetsenLin ~]# fdisk -l /dev/sdb 查看分區信息，類型是Linux，id是83
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 1024 8225248+ 83 Linux
/dev/sdb2 1025 2000 7839720 83 Linux
修改分區類型
[root@jetsenLin ~]# fdisk /dev/sdb
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)
Command (m for help): t ---進入修改分區類型
Partition number (1-4): 1 ---指定需要修改的分區號
Hex code (type L to list codes): 6 ---指定分區號為6，也就是FAT16
註意：查看分區類型的代碼，在這裏可以輸入L查看就可以了
Changed system type of partition 1 to 6 (FAT16)
Command (m for help): w ---保存
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.
Syncing disks.
[root@jetsenLin ~]# fdisk -l /dev/sdb ---我們看到已經FAT16，並且ID也改成6了。
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 1024 8225248+ 6 FAT16
/dev/sdb2 1025 2000 7839720 83 Linux
[root@jetsenLin ~]#
4、 對分區進行格式化及加載：
對分區進行格式化的命令如下等，mkfs後面所接的代表的是將要格式化成的文件系統類型：
mkfs.bfs
mkfs.ext2
mkfs.ext3
mkfs.jfs
mkfs.msdos
mkfs.vfat
mkfs.cramfs
mkfs.minix
mkfs.reiserfs
mkfs.xfs
格式化分區：
[root@jetsenLin ~]# mkfs.ext4 /dev/sdb1 ---格式化分區類型為ext4
mke4fs 1.41.5 (23-Apr-2009)
Filesystem label= ---我們沒有指定卷標，就沒有
OS type: Linux ---操作系統類型
Block size=4096 (log=2) --單個塊的大小
Fragment size=4096 (log=2) --片大小
1310720 inodes, 5241198 blocks
262059 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
160 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
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 27 mounts or
180 days, whichever comes first. Use tune4fs -c or -i to override.
掛載磁盤：（臨時掛載）
[root@jetsenLin ~]# mkdir /data --創建掛載目錄點
[root@jetsenLin ~]# mount /dev/sdb1 /data --將/dev/sdb1 掛載到/data
驗證是否成功掛載
[root@jetsenLin ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
7.7G 3.1G 4.2G 43% /
/dev/sda1 99M 12M 82M 13% /boot
tmpfs 506M 0 506M 0% /dev/shm
/dev/sdb1 20G 16K 20G 1% /data --我們看到已經成功掛載了。
[root@jetsenLin ~]#
掛載磁盤：（永久掛載）
通過vi編輯器編輯/etc/fstab文件，內容如下，（紅色部分是剛添加上去的）：
掛載路徑 掛載的分區 文件系統 掛載參數 是否要備份 自檢順序
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
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/VolGroup00/LogVol01 swap swap defaults 0 0
/data /dev/sdb1 ext4 default 0 0
第四列掛載參數：通過查看man mount 來查看
第五列是否要備份：（0為不備份，1為要備份， 一般情況下不用做備份）
第六列自檢程序 （0為不自檢，1或2為要自檢，如果是根分區要設置1，其它分區只能是2）
============ End
Fdisk 分區詳解