分区工具fdisk，gdisk，parted

在linux中，当我们给系统添加一块新硬盘时，我们是无法使用的，因为他还没有分区和格式化，只有当我们将新硬盘分区并格式化之后，挂载在某个目录下，才能供我们正常使用，接下来我们要学习三种硬盘分区工具，fdisk，gdisk，parted，分别是针对于MBR分区格式，GPT分区格式，高级分区工具（可以针对于上面两种进行分区，使用起来也是比较复杂的），关于MBR和GPT请参考硬盘结构基础

fdisk（MBR）

fdisk

-l /dev/sdX 查看硬盘分区信息

-c （centos6) 打开或禁用dos模式

-u  (centos6) 切换显示的单位(扇区/柱面)

-c (centos7) -c=dos -c=nondos

-u  (centos7)  -u=cylinders  -u=sectors

fdisk /dev/sdX  进行分区

m 帮助

n 建立分区

d 删除分区

p 显示分区信息

t 转换分区类型

a 将指定分区设置/取消 活动分区

L 查看分区类型

o 重建分区表

v 验证分区表，显示剩余没有被分区划分的扇区数量

g 创建GPT格式的分区（centos7)

q 退出不保存，不保存，所有的修改都不生效

w 退出并保存

[root@CT6 ~]# fdisk -l /dev/sdb                         

WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.

Disk /dev/sdb: 536.9 GB,  bytes　　-------------------------硬盘大小
 heads,  sectors/track,  cylinders　　------------------------磁头数，每磁道扇区数，柱面数
Units = cylinders of  *  =  bytes　　--------------------每柱面大小
Sector size (logical/physical):  bytes /  bytes　　---------------扇区大小
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x00000000　　-----------------------------------------未分区磁盘

[root@CT6 ~]# fdisk /dev/sdb   --------------------------磁盘分区

WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util fdisk doesn't support GPT. Use GNU Parted.

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x52ce01ab.
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 ------------------------查看帮助
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): 

Command (m for help): n   ------------------------------添加一个分区
Command action
   e   extended
   p   primary partition (-)
p　　　　　　---------------------------------------------添加主分区
Partition number (-): 1　　----------------------------磁盘编号1，即：sdb1
First cylinder (-, default ): -------------------开始位置，不填写，默认就行
Using default value
Last cylinder, +cylinders or +size{K,M,G} (-, default ): +20G -----------填写大小

Command (m for help): p  --------------------------------查看刚刚的分区

Disk /dev/sdb: 536.9 GB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x52ce01ab

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1                           +    Linux　　-----------------创建了一个分区

Command (m for help): l  ------------------查看可用的分区类型

   Empty             NEC DOS           Minix / old Lin bf  Solaris
   FAT12             Plan             Linux swap / So c1  DRDOS/sec (FAT-
   XENIX root      3c  PartitionMagic    Linux           c4  DRDOS/sec (FAT-
   XENIX usr         Venix        OS/ hidden C:  c6  DRDOS/sec (FAT-
   FAT16 <32M        PPC PReP Boot     Linux extended  c7  Syrinx
   Extended          SFS               NTFS volume set da  Non-FS data
   FAT16           4d  QNX4.x            NTFS volume set db  CP/M / CTOS / .
   HPFS/NTFS       4e  QNX4.x 2nd part   Linux plaintext de  Dell Utility
   AIX             4f  QNX4.x 3rd part 8e  Linux LVM       df  BootIt
   AIX bootable      OnTrack DM        Amoeba          e1  DOS access
 a  OS/ Boot Manag   OnTrack DM6 Aux   Amoeba BBT      e3  DOS R/O
 b  W95 FAT32         CP/M            9f  BSD/OS          e4  SpeedStor
 c  W95 FAT32 (LBA)   OnTrack DM6 Aux a0  IBM Thinkpad hi eb  BeOS fs
 e  W95 FAT16 (LBA)   OnTrackDM6      a5  FreeBSD         ee  GPT
 f  W95 Ext'd (LBA) 55  EZ-Drive        a6  OpenBSD         ef  EFI (FAT-12/16/
  OPUS              Golden Bow      a7  NeXTSTEP        f0  Linux/PA-RISC b
  Hidden FAT12    5c  Priam Edisk     a8  Darwin UFS      f1  SpeedStor
  Compaq diagnost   SpeedStor       a9  NetBSD          f4  SpeedStor
  Hidden FAT16 <   GNU HURD or Sys ab  Darwin boot     f2  DOS secondary
  Hidden FAT16      Novell Netware  af  HFS / HFS+      fb  VMware VMFS
  Hidden HPFS/NTF   Novell Netware  b7  BSDI fs         fc  VMware VMKCORE
  AST SmartSleep    DiskSecure Mult b8  BSDI swap       fd  Linux raid auto
1b  Hidden W95 FAT3   PC/IX           bb  Boot Wizard hid fe  LANstep
1c  Hidden W95 FAT3   Old Minix       be  Solaris boot    ff  BBT
1e  Hidden W95 FAT1

Command (m for help): 

Command (m for help): w　　-----------------------保存并退出
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

gdisk（GPT）

gdisk

-l /dev/sdX 查看分区信息

gdisk

(?|m) 帮助

n 建立分区

d 删除分区

c 更改分区名字

　   I 显示分区的详细信息

p 显示分区信息

t转换分区类型

a 将指定分区设置/取消 活动分区

l 查看分区类型

o 重建分区表

v 验证分区表，显示剩余没有被分区划分的扇区数量

q 退出不保存，不保存，所有的修改都不生效

w 退出并保存

gdisk时用来创建GPT分区的，我们可以看到，gdisk和fdisk的开头是有些不同的。

[root@CT6 ~]# gdisk /dev/sdb
GPT fdisk (gdisk) version 0.8.

Partition table scan:
  MBR: not present
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with corrupt MBR; using GPT and will write new
protective MBR on save.

Command (? for help): 

一个GPT分区

Command (? for help): o
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): y

Command (? for help): p
Disk /dev/sdb:  sectors, 500.0 GiB ----------------磁盘大小，显示扇区数
Logical sector size:  bytes　　---------------------------扇区大小
Disk identifier (GUID): E072194E-C4DA-449B-9CF9-E5171235E6D3
Partition table holds up to  entries
First usable sector is , last usable sector is 1048575966 -------------------第一个有用的扇区在34，最后一个有用的扇区在104857966
Partitions will be aligned on -sector boundaries
Total free space is  sectors (500.0 GiB)

Number  Start (sector)    End (sector)  Size       Code  Name

Command (? for help):

更改磁盘的类型

Command (? for help): t　　------------------------------------------更改磁盘类型
Using
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = ): 8e00
Changed type of partition to 'Linux LVM'　　-------------------------更改为"Linux LVM"

Command (? for help): p
Disk /dev/sdb:  sectors, 500.0 GiB
Logical sector size:  bytes
Disk identifier (GUID): E072194E-C4DA-449B-9CF9-E5171235E6D3
Partition table holds up to  entries
First usable sector is , last usable sector is
Partitions will be aligned on -sector boundaries
Total free space is  sectors (400.0 GiB)

Number  Start (sector)    End (sector)  Size       Code  Name
                         100.0 GiB   8E00  Linux LVM ------------------------ 改过了

Command (? for help): 

当我们查看磁盘的时候，我们首先要看磁盘是那种分区格式的，如果是MBR分区格式，我们最好使用fdisk –l，要是为GPT分区格式的硬盘，我们就使用gdisk –l来查看。因为fdisk查看GPT格式的磁盘最大能看到2T，再多的磁盘分区就无法查看，还会出错。

parted(高级分区工具)

parted命令是由GNU组织开发的一款功能强大的磁盘分区和分区大小调整工具，与fdisk不同，它支持调整分区的大小。作为一种设计用于Linux的工具，它没有构建成处理与fdisk关联的多种分区类型，但是，它可以处理最常见的分区格式，包括：ext2、ext3、fat16、fat32、NTFS、ReiserFS、JFS、XFS、UFS、HFS以及Linux交换分区。

parted

-h 显示帮助信息

-l 显示磁盘信息

-s 脚本模式，不提示用户

-v 显示版本号

[root@CT6 ~]# parted -h
Usage: parted [OPTION]... [DEVICE [COMMAND [PARAMETERS]...]...]
Apply COMMANDs with PARAMETERS to DEVICE.  If no COMMAND(s) are given, run in
interactive mode.

OPTIONs:
  -h, --help                      displays this help message
  -l, --list                      lists partition layout on all block devices
  -m, --machine                   displays machine parseable output
  -s, --script                    never prompts for user intervention
  -v, --version                   displays the version
  -a, --align=[none|cyl|min|opt]  alignment for new partitions

COMMANDs:
  align-check TYPE N                        check partition N for TYPE(min|opt)
        alignment
  check NUMBER                             do a simple check on the file system
  cp [FROM-DEVICE] FROM-NUMBER TO-NUMBER   copy file system to another partition
　　... ...

[root@CT6 ~]# parted -l
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sda: 215GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type      File system     Flags
       1049kB  1075MB  1074MB  primary   ext4            boot
       1075MB  .8GB  .7GB  primary   ext4
       .8GB  108GB   .7GB  primary   ext4
       108GB   215GB   106GB   extended
       108GB   113GB   4295MB  logical   linux-swap(v1)
       113GB   134GB   .5GB  logical

parted /dev/sdX 分区

mklabel label_type 设置分区格式（MBR，GPT）

mkpart part-type [fs-type] start end(单位Mb)设置分区

print 查看分区信息

help [command] 查看命令[command]如何使用

rm num 删除一个分区

set num flag status 设置flag（boot，root，swap）状态（on，off）

quit 退出

开始分区

[root@CT6 ~]# parted /dev/sdb
GNU Parted 2.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) 

查看帮助

(parted) help
  align-check TYPE N                        check partition N for TYPE(min|opt) alignment
  check NUMBER                             do a simple check on the file system
  cp [FROM-DEVICE] FROM-NUMBER TO-NUMBER   copy file system to another partition
  help [COMMAND]                           print general help, or help on COMMAND　　--------------------查看命令如何使用
  mklabel,mktable LABEL-TYPE               create a new disklabel (partition table)　　------------------设置磁盘类型
  mkfs NUMBER FS-TYPE                      make a FS-TYPE file system on partition NUMBER
  mkpart PART-TYPE [FS-TYPE] START END     make a partition　　-------------------------------------------磁盘分区
  mkpartfs PART-TYPE FS-TYPE START END     make a partition with a file system
  move NUMBER START END                    move partition NUMBER
  name NUMBER NAME                         name partition NUMBER as NAME
  print [devices|free|list,all|NUMBER]     display the partition table, available devices, --------------查看分区
        free space, all found partitions, or a particular partition
  quit                                     exit program
  rescue START END                         rescue a lost partition near START and END
  resize NUMBER START END                  resize partition NUMBER and its file system
  rm NUMBER                                delete partition NUMBER　　-----------------------------------删除分区
  select DEVICE                            choose the device to edit
  set NUMBER FLAG STATE                    change the FLAG on partition NUMBER
  toggle [NUMBER [FLAG]]                   toggle the state of FLAG on partition NUMBER
  unit UNIT                                set the default unit to UNIT
  version                                  display the version number and copyright
        information of GNU Parted
(parted)          

(parted) help mklabel
  mklabel,mktable LABEL-TYPE               create a new disklabel (partition table)

        LABEL-TYPE is one of: aix, amiga, bsd, dvh, gpt, mac, msdos, pc98, sun, loop --------------可以设置的类型
(parted)                                                                  

(parted) mklabel gpt　　------------------------------设置GPT分区
(parted) print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start  End  Size  File system  Name  Flags

(parted) 

(parted) help mkpart           ----------------------------------查看分区命令如何用
  mkpart PART-TYPE [FS-TYPE] START END     make a partition

        PART-TYPE is one of: primary, logical, extended
        FS-TYPE is one of: ext4, ext3, ext2, fat32, fat16, hfsx, hfs+, hfs, jfs, swsusp,
        linux-swap(v1), linux-swap(v0), ntfs, reiserfs, hp-ufs, sun-ufs, xfs, apfs2, apfs1,
        asfs, amufs5, amufs4, amufs3, amufs2, amufs1, amufs0, amufs, affs7, affs6, affs5,
        affs4, affs3, affs2, affs1, affs0, linux-swap, linux-swap(new), linux-swap(old)
        START and END are disk locations, such as 4GB or 10%.  Negative values count from
        the end of the disk.  For example, -1s specifies exactly the last sector.

        'mkpart' makes a partition without creating a new file system on the partition.
        FS-TYPE may be specified to set an appropriate partition ID.
(parted) mkpart primary  200G 　　-------------------------------------------------设置分区
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? ignore
(parted) print                   -----------------------------------------------------查看分区
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End    Size   File system  Name     Flags
       .4kB  200GB  200GB               primary　　　　-------------------------------分区大小

(parted) quit
Information: You may need to update /etc/fstab. 

这个命令是一个实时生效的命令，当我们分完一个区后，不用结束就可以直接生效，不像fdisk和gdisk那样需要退出后才保存生效。

lsblk

列出块设备

lsblk命令用于列出所有可用块设备的信息，而且还能显示他们之间的依赖关系，但是它不会列出RAM盘的信息。块设备有硬盘，闪存盘，cd-ROM等等

如：

lsblk /dev/sdb

[root@CT6 ~]# lsblk /dev/sda
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      :      200G   disk
├─sda1   :        1G   part /boot
├─sda2   :       50G   part /
├─sda3   :       50G   part /app
├─sda4   :        1K   part
├─sda5   :        4G   part [SWAP]
└─sda6   :       20G   part 

查看内核是否已经识别新的分区：

cat
/proc/partations

[root@CT6 ~]# cat /proc/partitions
major minor  #blocks  name

              sda
                sda1
               sda2
               sda3
                      sda4
                sda5
               sda6
             sdb
             sdb1

我们在原硬盘未使用的空间进行分区后，在物理设备上已经完成了，使用fdisk -l可以查看到，但是内存信息中并没有新的分区信息，此时我们需要手动更新分区表，在centOS6中使用partx，在5 或者7中可以使用partprobe（这个在6中有BUG）

partx -a /dev/sda 更新内存中的磁盘分区表信息

partx -d --nr 6 /dev/sda 删除掉在内存中的已经删除的第六块分区的信息

刚开始我们就五个分区，无论是内存中的信息，还是物理硬盘

[root@CT6 ~]# lsblk /dev/sda
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      :      200G   disk
├─sda1   :        1G   part /boot
├─sda2   :       50G   part /
├─sda3   :       50G   part /app
├─sda4   :        1K   part
└─sda5   :        4G   part [SWAP]

[root@CT6 ~]# fdisk -l /dev/sda | grep "^/dev/sda*"
/dev/sda1   *                              Linux
/dev/sda2                              Linux
/dev/sda3                            Linux
/dev/sda4                           Extended
/dev/sda5                            Linux swap / Solaris

接下来，我们创建一个分区

Command (m for help): n
First cylinder (-, default ):
Last cylinder, +cylinders or +size{K,M,G} (-, default ): +10G

Command (m for help): p

Disk /dev/sda: 214.7 GB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x0007a903

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *                              Linux
/dev/sda2                              Linux
/dev/sda3                            Linux
/dev/sda4                           Extended
/dev/sda5                            Linux swap / Solaris
/dev/sda6                      +    Linux

Command (m for help): w
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 or after you run partprobe(8) or kpartx(8)
Syncing disks.

我们在分完区以后，如上，显示的红色字体，我们刚刚分好的区并没有被读入内存当中，也就是说我们fdisk可以读到，但是lsblk却无法读到

[root@CT6 ~]# fdisk -l /dev/sda | grep "^/dev/sda.*"
/dev/sda1   *                              Linux
/dev/sda2                              Linux
/dev/sda3                            Linux
/dev/sda4                           Extended
/dev/sda5                            Linux swap / Solaris
/dev/sda6           14000       15305    10490444+  83  Linux
[root@CT6 ~]# lsblk /dev/sda
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      :      200G   disk
├─sda1   :        1G   part /boot
├─sda2   :       50G   part /
├─sda3   :       50G   part /app
├─sda4   :        1K   part
└─sda5   :        4G   part [SWAP]

接下来我们更新一下分区信息

[root@CT6 ~]# partx -a /dev/sda
BLKPG: Device or resource busy
error adding partition
BLKPG: Device or resource busy
error adding partition
BLKPG: Device or resource busy
error adding partition
BLKPG: Device or resource busy
error adding partition
BLKPG: Device or resource busy
error adding partition
[root@CT6 ~]# lsblk /dev/sda
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      :      200G   disk
├─sda1   :        1G   part /boot
├─sda2   :       50G   part /
├─sda3   :       50G   part /app
├─sda4   :        1K   part
├─sda5   :        4G   part [SWAP]
└─sda6   8:6    0   10G  0 part