【CentOS 7筆記19】，磁盤分區#

hellopasswd

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使用fdisk命令查看當前已有的磁盤

[root@localhost ~]# fdisk -l

	Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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 label type: dos
	Disk identifier: 0x000c37f3

	   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    62914559    29154304   83  Linux

添加虛擬機硬盤（設置->添加）

• 磁盤 10G

[root@localhost ~]# reboot
[root@localhost ~]# fdisk -l

	Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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 label type: dos
	Disk identifier: 0x000c37f3

	   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    62914559    29154304   83  Linux

	Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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

fdisk用法

[root@localhost ~]# fdisk /dev/sdb
	Welcome to fdisk (util-linux 2.23.2).

	Changes will remain in memory only, until you decide to write them.
	Be careful before using the write command.

	Device does not contain a recognized partition table
	Building a new DOS disklabel with disk identifier 0xfdc0e468.

	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
	   g   create a new empty GPT partition table
	   G   create an IRIX (SGI) partition table
	   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)

經常使用命令

d   delete a partition
	l   list known partition types
	n   add a new partition
	p   print the partition table
	q   quit without saving changes
	w   write table to disk and exit
	t   change a partition's system id

p查看當前分區表

Command (m for help): p

	Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
	Disk identifier: 0xfdc0e468

	Device Boot      Start         End      Blocks   Id  System

n新建分區表

Command (m for help): n
    Partition type:
       p   primary (0 primary, 0 extended, 4 free)    #主分區，最多能創建4個
       e   extended    #擴展分區
    Select (default p): p
    Partition number (1-4, default 1): 1    #使用分區號
    First sector (2048-20971519, default 2048):     #選擇扇區，回車
    Using default value 2048    #默認從2048開始
    Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): +2G    #劃分2G
    Partition 1 of type Linux and of size 2 GiB is set    #分區1大小爲2G

    Command (m for help): p

    Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
    Disk identifier: 0x330f2615

       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048     4196351     2097152   83  Linux

    Command (m for help):

l查看分區類型

Command (m for help): l

	 0  Empty           24  NEC DOS         81  Minix / old Lin bf  Solaris        
	 1  FAT12           27  Hidden NTFS Win 82  Linux swap / So c1  DRDOS/sec (FAT-
	 2  XENIX root      39  Plan 9          83  Linux           c4  DRDOS/sec (FAT-
	 3  XENIX usr       3c  PartitionMagic  84  OS/2 hidden C:  c6  DRDOS/sec (FAT-
	 4  FAT16 <32M      40  Venix 80286     85  Linux extended  c7  Syrinx         
	 5  Extended        41  PPC PReP Boot   86  NTFS volume set da  Non-FS data    
	 6  FAT16           42  SFS             87  NTFS volume set db  CP/M / CTOS / .
	 7  HPFS/NTFS/exFAT 4d  QNX4.x          88  Linux plaintext de  Dell Utility   
	 8  AIX             4e  QNX4.x 2nd part 8e  Linux LVM       df  BootIt         
	 9  AIX bootable    4f  QNX4.x 3rd part 93  Amoeba          e1  DOS access     
	 a  OS/2 Boot Manag 50  OnTrack DM      94  Amoeba BBT      e3  DOS R/O        
	 b  W95 FAT32       51  OnTrack DM6 Aux 9f  BSD/OS          e4  SpeedStor      
	 c  W95 FAT32 (LBA) 52  CP/M            a0  IBM Thinkpad hi eb  BeOS fs        
	 e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a5  FreeBSD         ee  GPT            
	 f  W95 Ext'd (LBA) 54  OnTrackDM6      a6  OpenBSD         ef  EFI (FAT-12/16/
	10  OPUS            55  EZ-Drive        a7  NeXTSTEP        f0  Linux/PA-RISC b
	11  Hidden FAT12    56  Golden Bow      a8  Darwin UFS      f1  SpeedStor      
	12  Compaq diagnost 5c  Priam Edisk     a9  NetBSD          f4  SpeedStor      
	14  Hidden FAT16 <3 61  SpeedStor       ab  Darwin boot     f2  DOS secondary  
	16  Hidden FAT16    63  GNU HURD or Sys af  HFS / HFS+      fb  VMware VMFS    
	17  Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fc  VMware VMKCORE 
	18  AST SmartSleep  65  Novell Netware  b8  BSDI swap       fd  Linux raid auto
	1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid fe  LANstep        
	1c  Hidden W95 FAT3 75  PC/IX           be  Solaris boot    ff  BBT            
	1e  Hidden W95 FAT1 80  Old Minix      

	Command (m for help):

t改變分區系統

Command (m for help): t
	Selected partition 1
	Hex code (type L to list all codes): 8e
	Changed type of partition 'Linux' to 'Linux LVM'

d刪除分區

Command (m for help): d
    Selected partition 1
    Partition 1 is deleted

    Command (m for help): p

    Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
    Disk identifier: 0x330f2615

       Device Boot      Start         End      Blocks   Id  System

    Command (m for help):

演示

Command (m for help): p

    Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
    Disk identifier: 0xa8f0c23e

       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048     2099199     1048576   83  Linux
    /dev/sdb2         2099200     6293503     2097152   83  Linux
    /dev/sdb3         6293504     8390655     1048576   83  Linux
    /dev/sdb4         8390656    18876415     5242880    5  Extended
    /dev/sdb5         8392704    10489855     1048576   83  Linux
    /dev/sdb6        10491904    14686207     2097152   83  Linux
    /dev/sdb7        14688256    18876415     2094080   83  Linux

    Command (m for help): d
    Partition number (1-7, default 7): 1
    Partition 1 is deleted

    Command (m for help): d
    Partition number (2-7, default 7): 5
    Partition 5 is deleted

    Command (m for help): p

    Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 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 label type: dos
    Disk identifier: 0xa8f0c23e

       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb2         2099200     6293503     2097152   83  Linux
    /dev/sdb3         6293504     8390655     1048576   83  Linux
    /dev/sdb4         8390656    18876415     5242880    5  Extended
    /dev/sdb5        10491904    14686207     2097152   83  Linux
    /dev/sdb6        14688256    18876415     2094080   83  Linux

    Command (m for help):

83爲主分區和邏輯分區，5爲擴展分區
新建三個主分區分別爲sdb一、sdb二、sdb3，一個擴展分區分3個邏輯分區sdb四、sdb五、sdb6。將分區sdb1刪除，則能夠發現分區1爲空，而將sdb4，則後續的sdb五、sdb6變成爲sdb四、sdb5
在建立磁盤分區時，有三種方式，分別爲主分區（p），擴展分區（e），邏輯分區（l）
建立分區最多可以建立4個分區（4箇中不包括邏輯分區），若要建立多個分區，能夠建立3個或3個如下主分區再配合1個擴展分區組合
在擴展分區中，建立邏輯分區（能夠建立無限個邏輯分區）。
當刪除擴展分區時，所分配的邏輯分區也會一併刪除