ubuntu 磁盘分区

1:查看分区情况：df -h

admin@iZwz92c0zpe8t65qe996ckZ:/$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            983M       983M   % /dev
tmpfs           201M   24M  177M  % /run
/dev/vda1        40G  .3G   28G  % /
tmpfs          1001M      1001M   % /dev/shm
tmpfs           5.0M  .0K  5.0M   % /run/lock
tmpfs          1001M      1001M   % /sys/fs/cgroup
tmpfs           201M       201M   % /run/user/

2：查看某一个目录挂载在哪一个分区下面：df -h 目录

admin@iZwz92c0zpe8t65qe996ckZ:/$ df -h /srv/
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        40G  .3G   28G  % /

3：给磁盘进行分区：sudo fdisk /dev/vda

admin@iZwz92c0zpe8t65qe996ckZ:/$ sudo fdisk /dev/vda

Welcome to fdisk (util-linux 2.27.).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Command (m for help): m

使用m查看命令的使用方法

  Misc
   m   print this menu
   u   change display/entry units
   x   extra functionality (experts only)

  Script
   I   load disk layout from sfdisk script file
   O   dump disk layout to sfdisk script file

  Save & Exit
   w   write table to disk and exit
   q   quit without saving changes

  Create a new label
   g   create a new empty GPT partition table
   G   create a new empty SGI (IRIX) partition table
   o   create a new empty DOS partition table
   s   create a new empty Sun partition table

Command (m for help):

命令p打印分区情况：

Command (m for help): p
Disk /dev/vda:  GiB,  bytes,  sectors
Units: sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disklabel type: dos
Disk identifier: 0xd6804155

Device     Boot Start      End  Sectors Size Id Type
/dev/vda1  *         40G  Linux

d 删除分区

命令n 添加分区：

Command (m for help): d
Selected partition
Partition  has been deleted.

Command (m for help): n
Partition type
   p   primary ( primary,  extended,  free)
   e   extended (container for logical partitions)
Select (default p):

添加分区

Select (default p): p
Partition number (-, default ):
First sector (-, default ):
Last sector, +sectors or +size{K,M,G,T,P} (-, default ): 

Created a new partition  of type 'Linux' and of size 19.1 GiB.

Command (m for help): p
Disk /dev/vda:  GiB,  bytes,  sectors
Units: sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disklabel type: dos
Disk identifier: 0xd6804155

Device     Boot Start      End  Sectors  Size Id Type
/dev/vda1           .1G  Linux

再添加一个分区：

Using default response p.
Partition number (-, default ):
First sector (-, default ):
Last sector, +sectors or +size{K,M,G,T,P} (-, default ): 

Created a new partition  of type 'Linux' and of size 20.9 GiB.

Command (m for help): p
Disk /dev/vda:  GiB,  bytes,  sectors
Units: sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disklabel type: dos
Disk identifier: 0xd6804155

Device     Boot    Start      End  Sectors  Size Id Type
/dev/vda1              .1G  Linux
/dev/vda2          .9G  Linux

使用命令w保存修改

命令q是修改失效，上面修改没用

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Re-reading the partition table failed.: 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() or kpartx().

执行 partprobe

admin@iZwz92c0zpe8t65qe996ckZ:~$ partprobe

提示 /dev/vda2不存在

执行：sudo mknod /dev/vda2 b 8 4     http://blog.itpub.net/28874898/viewspace-774249/

admin@iZwz92c0zpe8t65qe996ckZ:~$ sudo mknod  /dev/vda2  b
sudo: unable to resolve host iZwz92c0zpe8t65qe996ckZ
admin@iZwz92c0zpe8t65qe996ckZ:~$ ll /dev/vda*
brw-rw----  root disk ,  Oct  : /dev/vda
brw-rw----  root disk ,  Oct  : /dev/vda1
brw-r--r--  root root   ,  Oct  : /dev/vda2

3:卸载磁盘挂载：

admin@iZwz92c0zpe8t65qe996ckZ:/$ sudo umount /dev/vda
sudo: unable to resolve host iZwz92c0zpe8t65qe996ckZ
umount: /dev/vda: not mounted

4：阿里云安装完系统之后，只有一个分区，想要变成多个分区？

可以先缩小分区的容量，然后用多余的容量去再分区。