fdisk
查看磁盘使用情况和磁盘分区
补充说明
fdisk命令 用于观察硬盘实体使用情况，也可对硬盘分区。它采用传统的问答式界面，而非类似DOS fdisk的cfdisk互动式操作界面，因此在使用上较为不便，但功能却丝毫不打折扣。
语法
1fdisk(选项)(参数)
选项
1 -b <大小> 扇区大小(512、1024、2048或4096)
2 -c[=<模式>] 兼容模式：“dos”或“nondos”(默认)
3 -h 打印此帮助文本
4 -u[=<单位>] 显示单位：“cylinders”(柱面)或“sectors”(扇区，默认)
5 -v 打印程序版本
6 -C <数字> 指定柱面数
7 -H <数字> 指定磁头数
8 -S <数字> 指定每个磁道的扇区数
参数
设备文件：指定要进行分区或者显示分区的硬盘设备文件。
实例
首先选择要进行操作的磁盘：
1[[email protected] ~]# fdisk /dev/sdb
输入m列出可以执行的命令：
1command (m for help): m
2Command action
3 a toggle a bootable flag
4 b edit bsd disklabel
5 c toggle the dos compatibility flag
6 d delete a partition
7 l list known partition types
8 m print this menu
9 n add a new partition
10 o create a new empty DOS partition table
11 p print the partition table
12 q quit without saving changes
13 s create a new empty Sun disklabel
14 t change a partition's system id
15 u change display/entry units
16 v verify the partition table
17 w write table to disk and exit
18 x extra functionality (experts only)
输入p列出磁盘目前的分区情况：
1Command (m for help): p
2
3Disk /dev/sdb: 3221 MB, 3221225472 bytes
4255 heads, 63 sectors/track, 391 cylinders
5Units = cylinders of 16065 * 512 = 8225280 bytes
6
7 Device Boot Start End Blocks Id System
8/dev/sdb1 1 1 8001 8e Linux LVM
9/dev/sdb2 2 26 200812+ 83 Linux
输入d然后选择分区，删除现有分区：
1Command (m for help): d
2Partition number (1-4): 1
3
4Command (m for help): d
5Selected partition 2
查看分区情况，确认分区已经删除：
1Command (m for help): print
2
3Disk /dev/sdb: 3221 MB, 3221225472 bytes
4255 heads, 63 sectors/track, 391 cylinders
5Units = cylinders of 16065 * 512 = 8225280 bytes
6
7 Device Boot Start End Blocks Id System
8
9Command (m for help):
输入n建立新的磁盘分区，首先建立两个主磁盘分区：
1Command (m for help): n
2Command action
3 e extended
4 p primary partition (1-4)
5p //建立主分区
6Partition number (1-4): 1 //分区号
7First cylinder (1-391, default 1): //分区起始位置
8Using default value 1
9last cylinder or +size or +sizeM or +sizeK (1-391, default 391): 100 //分区结束位置，单位为扇区
10
11Command (m for help): n //再建立一个分区
12Command action
13 e extended
14 p primary partition (1-4)
15p
16Partition number (1-4): 2 //分区号为2
17First cylinder (101-391, default 101):
18Using default value 101
19Last cylinder or +size or +sizeM or +sizeK (101-391, default 391): +200M //分区结束位置，单位为M
确认分区建立成功：
1Command (m for help): p
2
3Disk /dev/sdb: 3221 MB, 3221225472 bytes
4255 heads, 63 sectors/track, 391 cylinders
5Units = cylinders of 16065 * 512 = 8225280 bytes
6
7 Device Boot Start End Blocks Id System
8/dev/sdb1 1 100 803218+ 83 Linux
9/dev/sdb2 101 125 200812+ 83 Linux
再建立一个逻辑分区：
1Command (m for help): n
2Command action
3 e extended
4 p primary partition (1-4)
5e //选择扩展分区
6Partition number (1-4): 3
7First cylinder (126-391, default 126):
8Using default value 126
9Last cylinder or +size or +sizeM or +sizeK (126-391, default 391):
10Using default value 391
确认扩展分区建立成功：
1Command (m for help): p
2
3Disk /dev/sdb: 3221 MB, 3221225472 bytes
4255 heads, 63 sectors/track, 391 cylinders
5Units = cylinders of 16065 * 512 = 8225280 bytes
6
7 Device Boot Start End Blocks Id System
8/dev/sdb1 1 100 803218+ 83 Linux
9/dev/sdb2 101 125 200812+ 83 Linux
10/dev/sdb3 126 391 2136645 5 Extended
在扩展分区上建立两个逻辑分区：
1Command (m for help): n
2Command action
3 l logical (5 or over)
4 p primary partition (1-4)
5l //选择逻辑分区
6First cylinder (126-391, default 126):
7Using default value 126
8Last cylinder or +size or +sizeM or +sizeK (126-391, default 391): +400M
9
10Command (m for help): n
11Command action
12 l logical (5 or over)
13 p primary partition (1-4)
14l
15First cylinder (176-391, default 176):
16Using default value 176
17Last cylinder or +size or +sizeM or +sizeK (176-391, default 391):
18Using default value 391
确认逻辑分区建立成功：
1Command (m for help): p
2
3Disk /dev/sdb: 3221 MB, 3221225472 bytes
4255 heads, 63 sectors/track, 391 cylinders
5Units = cylinders of 16065 * 512 = 8225280 bytes
6
7 Device Boot Start End Blocks Id System
8/dev/sdb1 1 100 803218+ 83 Linux
9/dev/sdb2 101 125 200812+ 83 Linux
10/dev/sdb3 126 391 2136645 5 Extended
11/dev/sdb5 126 175 401593+ 83 Linux
12/dev/sdb6 176 391 1734988+ 83 Linux
13
14Command (m for help):
从上面的结果我们可以看到，在硬盘sdb我们建立了2个主分区（sdb1，sdb2），1个扩展分区（sdb3），2个逻辑分区（sdb5，sdb6）
注意：主分区和扩展分区的磁盘号位1-4，也就是说最多有4个主分区或者扩展分区，逻辑分区开始的磁盘号为5，因此在这个实验中试没有sdb4的。
最后对分区操作进行保存：
1Command (m for help): w
2The partition table has been altered!
3
4Calling ioctl() to re-read partition table.
5Syncing disks.
建立好分区之后我们还需要对分区进行格式化才能在系统中使用磁盘。
在sdb1上建立ext2分区：
1[[email protected] ~]# mkfs.ext2 /dev/sdb1
2mke2fs 1.39 (29-May-2006)
3Filesystem label=
4OS type: Linux
5Block size=4096 (log=2)
6Fragment size=4096 (log=2)
7100576 inodes, 200804 blocks
810040 blocks (5.00%) reserved for the super user
9First data block=0
10Maximum filesystem blocks=209715200
117 block groups
1232768 blocks per group, 32768 fragments per group
1314368 inodes per group
14Superblock backups stored on blocks:
15 32768, 98304, 163840
16
17Writing inode tables: done
18Writing superblocks and filesystem accounting information: done
19
20This filesystem will be automatically checked every 32 mounts or
21180 days, whichever comes first. Use tune2fs -c or -i to override.
在sdb6上建立ext3分区：
1[[email protected] ~]# mkfs.ext3 /dev/sdb6
2mke2fs 1.39 (29-May-2006)
3Filesystem label=
4OS type: Linux
5Block size=4096 (log=2)
6Fragment size=4096 (log=2)
7217280 inodes, 433747 blocks
821687 blocks (5.00%) reserved for the super user
9First data block=0
10Maximum filesystem blocks=444596224
1114 block groups
1232768 blocks per group, 32768 fragments per group
1315520 inodes per group
14Superblock backups stored on blocks:
15 32768, 98304, 163840, 229376, 294912
16
17Writing inode tables: done
18Creating journal (8192 blocks): done
19Writing superblocks and filesystem accounting information: done
20
21This filesystem will be automatically checked every 32 mounts or
22180 days, whichever comes first. Use tune2fs -c or -i to override.
23[[email protected] ~]#
建立两个目录/oracle和/web，将新建好的两个分区挂载到系统：
1[[email protected] ~]# mkdir /oracle
2[[email protected] ~]# mkdir /web
3[[email protected] ~]# mount /dev/sdb1 /oracle
4[[email protected] ~]# mount /dev/sdb6 /web
查看分区挂载情况：
1[[email protected] ~]# df -h
2文件系统 容量 已用 可用 已用% 挂载点
3/dev/mapper/VolGroup00-LogVol00
4 6.7G 2.8G 3.6G 44% /
5/dev/sda1 99M 12M 82M 13% /boot
6tmpfs 125M 0 125M 0% /dev/shm
7/dev/sdb1 773M 808K 733M 1% /oracle
8/dev/sdb6 1.7G 35M 1.6G 3% /web
如果需要每次开机自动挂载则需要修改/etc/fstab文件，加入两行配置：
1[[email protected] ~]# vim /etc/fstab
2
3/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
4LABEL=/boot /boot ext3 defaults 1 2
5tmpfs /dev/shm tmpfs defaults 0 0
6devpts /dev/pts devpts gid=5,mode=620 0 0
7sysfs /sys sysfs defaults 0 0
8proc /proc proc defaults 0 0
9/dev/VolGroup00/LogVol01 swap swap defaults 0 0
10/dev/sdb1 /oracle ext2 defaults 0 0
11/dev/sdb6 /web ext3 defaults 0 0
来源：https://github.com/jaywcjlove/linux-command