当新的硬件设备被添加到Linux中时,系统能自动识别,但新添加的硬盘必须要进行分区、格式化和挂载后才能使用。
MBR分区和fdisk
查看系统硬盘信息
fdisk -l
#硬盘sda的分区信息:
#sda被分成两个主分区sda1和sda3,一个swap分区sda2,一个扩展分区sda4,其中包含逻辑分区sda5
Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders, total 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e50ae
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 411647 204800 83 Linux
/dev/sda2 411648 4605951 2097152 82 Linux swap / Solaris
/dev/sda3 4605952 8701951 2048000 83 Linux
/dev/sda4 8701952 41943039 16620544 5 Extended
/dev/sda5 8704000 41943039 16619520 83 Linux
#硬盘sdb的信息:8GB空间,未分区
Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x740e36e3
Device Boot Start End Blocks Id System
进入硬盘sdb的分区模式
fdisk /dev/sdb
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').
#命令u:以扇区sector为单位分区
Command (m for help): u
Changing display/entry units to sectors
#划分主分区sdb1,并分配2GB空间
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First sector (63-16777215, default 63): #直接回车,采用默认值
Using default value 63
Last sector, +sectors or +size{K,M,G} (63-16777215, default 16777215): +2G
#划分扩展分区sdb2,并分配剩余所有磁盘空间
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4): 2
First sector (4194368-16777215, default 4194368):
Using default value 4194368
Last sector, +sectors or +size{K,M,G} (4194368-16777215, default 16777215):
Using default value 16777215
#划分逻辑分区sdb5,并分配2GB磁盘空间
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First sector (4194431-16777215, default 4194431):
Using default value 4194431
Last sector, +sectors or +size{K,M,G} (4194431-16777215, default 16777215): +2G
检查分区方案,将其写入磁盘分区表中
#命令p:打印磁盘分区方案(比上一步新增逻辑分区sdb6分配剩余所有空间)
Command (m for help): p
Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x740e36e3
Device Boot Start End Blocks Id System
/dev/sdb1 63 4194367 2097152+ 83 Linux
/dev/sdb2 4194368 16777215 6291424 5 Extended
/dev/sdb5 4194431 8388735 2097152+ 83 Linux
/dev/sdb6 8388799 16777215 4194208+ 83 Linux
#命令w:将分区信息写入磁盘并退出
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
p.s.
- fdisk分区工具采用交互式,即系统提问、用户作答响应的方式进行分区;
- 简单易懂、不易出错,但相较命令方式慢、效率低下;
- 可以随时使用m命令调用help;
- 分区结束不是即时生效的,要调用w命令将分区方案写入磁盘分区表。