Linux系统分区、磁盘挂载

1、fdisk -l命令：

 

1）添加磁盘之前，先用fdisk -l查看磁盘的基本信息

 

[root@localhost ~]# fdisk -l

 

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x0004cfc7

 

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          39      307200   83  Linux

Partition 1 does not end on cylinder boundary.（注：sda1的end和sda2的start，sda2的end和sda3的start都重复了，终端提 示： Partition 1 does not end on cylinder boundary。这句话的意思是说：分区 1 没有在柱面上结束）

/dev/sda2              39         549     4096000   82  Linux swap / Solaris

Partition 2 does not end on cylinder boundary.

/dev/sda3             549        5222    37538816   83  Linux

 

2）系统增加磁盘后，通过fdisk可以查看到新添加的磁盘信息

 

示例是在虚拟机运行的，关闭系统，在虚拟机的设置里，增加了一块20G的磁盘

 

[root@localhost oracle]# fdisk -l

 

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x0004cfc7

 

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          39      307200   83  Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2              39         549     4096000   82  Linux swap / Solaris

Partition 2 does not end on cylinder boundary.

/dev/sda3             549        5222    37538816   83  Linux

 

Disk /dev/sdb: 21.5 GB, 21474836480 bytes

255 heads, 63 sectors/track, 2610 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x782437c8

 

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1         654     5253223+  83  Linux

 

红色部分为新添加的磁盘信息

 

说明：Linux系统的分区格式使用的是xyzN的格式，xy表示的是硬盘类型，如上面的执行结果，sd表示是SCSI硬盘，z表示的是硬盘序号，第一块硬盘是a，第二块硬盘是b，所以要查询Linux系统上有几块硬盘，只要注意这一点即可。N表示的是分区号。

 

3）这个时候磁盘还不能挂载到系统，需要对新添加的磁盘进行分区

 

[root@localhost oracle]# 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').

 

Command (m for help): n（新建）

Command action

   e   extended

   p   primary partition (1-4)

p（主分区）

Partition number (1-4): 2（编号为2，在linux里最多只能建立四个主分区，所以通常至少建一个扩展分区，编号1-4为主分区的编号，逻辑分区的编号从5开始。如果只有一个主分区1，则2,3,4号空缺，直接从5号开始及1,5）

First cylinder (655-2610, default 655): 

Using default value 655

Last cylinder, +cylinders or +size{K,M,G} (655-2610, default 2610): +5G（用+表示分5G大小的磁盘空间）

 

Command (m for help): w（w表示保存）

The partition table has been altered!

 

Calling ioctl() to re-read partition table.

Syncing disks.

 

4）分区结束后，再次通过fdisk -l查询，结果如下：

 

[root@localhost oracle]# fdisk -l

 

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x0004cfc7

 

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          39      307200   83  Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2              39         549     4096000   82  Linux swap / Solaris

Partition 2 does not end on cylinder boundary.

/dev/sda3             549        5222    37538816   83  Linux

 

Disk /dev/sdb: 21.5 GB, 21474836480 bytes

255 heads, 63 sectors/track, 2610 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

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

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x782437c8

 

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1         654     5253223+  83  Linux

/dev/sdb2             655        1308     5253255   83  Linux（磁盘划分成功）

 

5）挂载之前需要对分区进行格式化，这里格式成ext4

 

[root@localhost oracle]# mkfs -t ext4 /dev/sdb2

mke2fs 1.41.12 (17-May-2010)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

328656 inodes, 1313313 blocks

65665 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=1346371584

41 block groups

32768 blocks per group, 32768 fragments per group

8016 inodes per group

Superblock backups stored on blocks: 

    32768, 98304, 163840, 229376, 294912, 819200, 884736

 

Writing inode tables: done                            

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

 

This filesystem will be automatically checked every 21 mounts or

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

[root@localhost oracle]# 

 

6)创建挂载点

 

[root@localhost oracle]# mkdir data

[root@localhost oracle]# 

 

 

7）通过mount挂载

 

[root@localhost oracle]# mount /dev/sdb1  /data

[root@localhost oracle]# 

 

注意：挂载点必须是一个目录，如果挂载之前，目录内有文件，则挂载后文件不可见

 

8)配置开机自启动

Vi /etc/fstab最后一行添加

/dev/sdb1 /data ext4 defaults 0 0

如果以上未能明白，这边推荐一个其他人写的文章：

https://blog.youkuaiyun.com/yangzhengquan19/article/details/83788277