linux命令之磁盘与文件系统管理命令（上）

1.fdisk：磁盘分区工具

该命令是linux下常用的磁盘分区工具，但是只能给小于2TB的磁盘划分分区。

常用参数为-l，显示所有磁盘分区的信息。

示例：

1）显示磁盘分区列表

[root@boxiaoyuan ~]# fdisk -l  # 查看当前系统的所有磁盘分区信息

Disk /dev/sda: 21.5 GB,  bytes  # 磁盘/dev/sda的大小

 heads,  sectors/track,  cylinders  # 255个虚拟磁头，63个扇区/磁道，2610个柱面

Units = cylinders of  *  =  bytes  # 一个柱面的大小为8225280bytes

Sector size (logical/physical):  bytes /  bytes  #每个扇区的字节数

I/O size (minimum/optimal):  bytes /  bytes  # 每次读写的字节数

Disk identifier: 0x0000db9b

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1                                 Linux swap / Solaris

/dev/sda2   *                         Linux

说明：Device表示分区；Boot表示启动分区，用*表示；Start表示开始的柱面；End表示结束的柱面；Blocks表示快数量；Id表示分区类型Id；System表示分区类型。

2）模拟分区实战

[root@boxiaoyuan ~]# fdisk /dev/sdb  # 不加参数，直接接设备名就可以进行分区

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel

Building a new DOS disklabel with disk identifier 0x784b7b62.

Changes will remain in memory only, until you decide to write them.

After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table  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').

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

   t   change a partition's system id

   u   change display/entry units

   v   verify the partition table

   w   write table to disk and exit

   x   extra functionality (experts only)

Command (m for help): n

Command action

   e   extended

   p   primary partition (-)

p

Partition number (-):

First cylinder (-, default ):

Using default value 

Last cylinder, +cylinders or +size{K,M,G} (-, default ): +100M

Command (m for help): p

Disk /dev/sdb:  MB,  bytes

 heads,  sectors/track,  cylinders

Units = cylinders of  *  =  bytes

Sector size (logical/physical):  bytes /  bytes

I/O size (minimum/optimal):  bytes /  bytes

Disk identifier: 0x784b7b62

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1                               +    Linux

Command (m for help): n

Command action

   e   extended

   p   primary partition (-)

e

Partition number (-):

First cylinder (-, default ):

Using default value 

Last cylinder, +cylinders or +size{K,M,G} (-, default ):

Using default value 

Command (m for help): p

Disk /dev/sdb:  MB,  bytes

 heads,  sectors/track,  cylinders

Units = cylinders of  *  =  bytes

Sector size (logical/physical):  bytes /  bytes

I/O size (minimum/optimal):  bytes /  bytes

Disk identifier: 0x784b7b62

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1                               +    Linux

/dev/sdb2                                   Extended



Command (m for help): n

Command action

   l   logical ( or over)

   p   primary partition (-)

p

Partition number (-): 

No free sectors available

Command (m for help): n

Command action

   l   logical ( or over)

   p   primary partition (-)

l

First cylinder (-, default ):

Using default value 

Last cylinder, +cylinders or +size{K,M,G} (-, default ): +400M

Command (m for help): p

Disk /dev/sdb:  MB,  bytes

 heads,  sectors/track,  cylinders

Units = cylinders of  *  =  bytes

Sector size (logical/physical):  bytes /  bytes

I/O size (minimum/optimal):  bytes /  bytes

Disk identifier: 0x784b7b62

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1                               +    Linux

/dev/sdb2                                   Extended

/dev/sdb5                              +    Linux

Command (m for help): n

Command action

   l   logical ( or over)

   p   primary partition (-)

l

First cylinder (-, default ):

Using default value 

Last cylinder, +cylinders or +size{K,M,G} (-, default ):

Using default value 

Command (m for help): p

Disk /dev/sdb:  MB,  bytes

 heads,  sectors/track,  cylinders

Units = cylinders of  *  =  bytes

Sector size (logical/physical):  bytes /  bytes

I/O size (minimum/optimal):  bytes /  bytes

Disk identifier: 0x784b7b62

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1                               +    Linux

/dev/sdb2                                   Extended

/dev/sdb5                              +    Linux

/dev/sdb6                             +    Linux

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

[root@boxiaoyuan ~]# partprobe /dev/sdb  # 执行该命令通知内核分区表已更新，不需要重启系统就可以让分区生效

格式化磁盘

[root@boxiaoyuan ~]# mkfs.ext4 /dev/sdb1

mke2fs 1.41. (-May-)

文件系统标签=

操作系统:Linux

块大小= (log=)

分块大小= (log=)

Stride= blocks, Stripe width= blocks

 inodes,  blocks

 blocks (5.00%) reserved for the super user

第一个数据块=

Maximum filesystem blocks=

 block groups

 blocks per group,  fragments per group

 inodes per group

Superblock backups stored on blocks:

        , , , , 

正在写入inode表: 完成

Creating journal ( blocks): 完成

Writing superblocks and filesystem accounting information: 完成

This filesystem will be automatically checked every  mounts or

 days, whichever comes first.  Use tune2fs -c or -i to override.

挂载磁盘

[root@boxiaoyuan ~]# mount /dev/sdb1 /mnt

[root@boxiaoyuan ~]# df -T

Filesystem     Type    1K-blocks    Used Available Use% Mounted on

/dev/sda2      ext4           % /

tmpfs          tmpfs                   % /dev/shm

/dev/sr0       iso9660              % /media/CentOS_6.8_Final

/dev/sdb1      ext4                   % /mnt

2.partprobe：更新内核的硬盘分区表信息

该命令用于在硬盘分区发生变化时，更新内核的硬盘分区表数据，可以在不重启系统时就更新分区表信息。

[root@boxiaoyuan ~]# partprobe /dev/sdb

3.parted：磁盘分区工具

该命令用于对大于2TB的磁盘进行分区，并且要将磁盘转换为GPT格式。

常用的参数选项为-l，显示所有磁盘分区的信息。

通过parted -h或者直接通过parted进入交互模式后通过-h查看帮助。

[root@boxiaoyuan ~]# parted

GNU Parted 2.1

使用 /dev/sda

Welcome to GNU Parted! Type 'help' to view a list of commands.

(parted) h

  align-check TYPE N

  check NUMBER

  cp [FROM-DEVICE] FROM-NUMBER TO-NUMBER

  help [COMMAND]

  mklabel,mktable LABEL-TYPE    # 创建分区表

  mkfs NUMBER FS-TYPE

  mkpart PART-TYPE [FS-TYPE] START END  # 创建分区

  mkpartfs PART-TYPE FS-TYPE START END  # 创建带有文件系统的分区

  move NUMBER START END

  name NUMBER NAME

  print [devices|free|list,all|NUMBER]    # 显示分区表信息

  quit

  rescue START END

  resize NUMBER START END

  rm NUMBER  # 删除编号NUMBER的分区

  select DEVICE

  set NUMBER FLAG STATE

  toggle [NUMBER [FLAG]]

  unit UNIT

  version

(parted)

示例：

1）显示分区情况

[root@boxiaoyuan ~]# parted -l

Model: VMware, VMware Virtual S (scsi)  # 磁盘类型

Disk /dev/sda: .5GB  # 磁盘大小

Sector size (logical/physical): 512B/512B  # 扇区大小

Partition Table: msdos  # 分区表类型

Number  Start   End     Size    Type     File system     标志

       1049kB  8591MB  8590MB  primary  linux-swap(v1)

       8591MB  .5GB  .9GB  primary  ext4            启动

2）模拟分区实战

[root@boxiaoyuan ~]# parted /dev/sdb  # parted直接接需要分区的设备

GNU Parted 2.1

使用 /dev/sdb

Welcome to GNU Parted! Type 'help' to view a list of commands.

(parted) mklabel gpt  # 为sdb磁盘创建GPT分区表，大于2TB的磁盘必须执行这一步

(parted) mkpart primary     # 创建主分区，500M

警告: The resulting partition is not properly aligned for best performance.

忽略/Ignore/放弃/Cancel? Ignore   # 忽略警告

(parted) p  # 显示分区表信息

Model: VMware, VMware Virtual S (scsi)

Disk /dev/sdb: 1074MB

Sector size (logical/physical): 512B/512B

Partition Table: gpt

Number  Start   End    Size   File system  Name     标志

       .4kB  500MB  500MB               primary

(parted) mkpart logical    # 创建逻辑分区，大小为500MB

(parted) p  # 显示分区表信息

Model: VMware, VMware Virtual S (scsi)

Disk /dev/sdb: 1074MB

Sector size (logical/physical): 512B/512B

Partition Table: gpt

Number  Start   End     Size   File system  Name     标志

       .4kB  500MB   500MB               primary

       501MB   1000MB  499MB               logical

(parted) quit  # 退出

信息: You may need to update /etc/fstab.                                  

[root@boxiaoyuan ~]# ls /dev/sdb*

/dev/sdb  /dev/sdb1  /dev/sdb2

[root@bixiaoyuan ~]# mkfs.ext4 /dev/sdb1  # 格式化

mke2fs 1.41. (-May-)

文件系统标签=

操作系统:Linux

块大小= (log=)

分块大小= (log=)

Stride= blocks, Stripe width= blocks

 inodes,  blocks

 blocks (5.00%) reserved for the super user

第一个数据块=

Maximum filesystem blocks=

 block groups

 blocks per group,  fragments per group

 inodes per group

Superblock backups stored on blocks:

        , , , , , , , 

正在写入inode表: 完成

Creating journal ( blocks): 完成

Writing superblocks and filesystem accounting information: 完成

This filesystem will be automatically checked every  mounts or

 days, whichever comes first.  Use tune2fs -c or -i to override.

[root@boxiaoyuan ~]# mount /dev/sdb1 /mnt  #挂载

4.mkfs：创建linux文件系统

该命令用于在指定的设备或者分区上创建格式化并创建文件系统。

常用的参数有-t：指定要创建的文件系统类型，也可以直接使用mkfs.ext4创建ext4文件系统。

5.df：报告文件系统磁盘空间的使用情况

该命令用于显示文件系统磁盘空间的使用情况。

参数	说明
-h（常用）	以容易理解的格式显示磁盘的使用情况
-i（常用）	显示文件系统的inode信息
-T（常用）	列出文件系统的类型

示例：

1）显示磁盘的使用情况

[root@boxiaoyuan ~]# df

Filesystem     1K-blocks    Used Available Use% Mounted on

/dev/sda2             % /

tmpfs                           % /dev/shm

2）-h选项

[root@boxiaoyuan ~]# df -h

Filesystem      Size  Used Avail Use% Mounted on

/dev/sda2        12G  .2G  .0G  % /

tmpfs           931M   72K  931M   % /dev/shm

3）列出文件系统的类型

[root@boxiaoyuan ~]# df -T

Filesystem     Type  1K-blocks    Used Available Use% Mounted on

/dev/sda2      ext4         % /

tmpfs          tmpfs                 % /dev/shm

注：本文内容为《跟老男孩学linux运维核心系统命令实践》的学习笔记。