CentOS 6.5挂载新硬盘

1 为什么要挂载

我们应该都知道，Linux里，没有C，D盘这样的概念，有的只有目录,一切都是以目录为标准。Linux将所有的硬件设备都当做文件来处理，因此当使用光驱等硬件设备时，必须将其挂载到系统中，只有这样Linux才能识别。

最基本的也是最上层的就是根目录(/)，下面可以有很多目录，根目录里可以加载成一个硬盘分区，下面的任意目录，也可以加载另一个硬盘分区，正是因为这种组织方式，挂载必须挂载到某个特定的目录中。

2 新建分区

2.1 添加硬盘

在服务器上新添加一块硬盘，重新启动，按F5进入开始做RAID，在此不做介绍。系统启动后通过fdisk查看所有分区信息。

<span style="font-size:12px;">[root@localhost ~]# fdisk -l

<span style="color:#ff0000;">Disk /dev/sdb: 599.9 GB, 599932844032 bytes</span>
255 heads, 63 sectors/track, 72937 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 524288 bytes
Disk identifier: 0xa70f5417

Disk /dev/sda: 300.0 GB, 299966445568 bytes
255 heads, 63 sectors/track, 36468 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 262144 bytes
Disk identifier: 0x00002b09

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              64       36469   292422656   8e  Linux LVM

Disk /dev/mapper/VolGroup-lv_root: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 262144 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_swap: 30.0 GB, 29993467904 bytes
255 heads, 63 sectors/track, 3646 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 262144 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_home: 215.8 GB, 215759192064 bytes
255 heads, 63 sectors/track, 26231 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 262144 bytes
Disk identifier: 0x00000000
</span>

通过查看，一块600GB的硬盘已添加成功。

2.2 分区操作

（1）显示帮助菜单，通过fdisk命令来为新的硬盘分区，通过fdisk命令查看，新的硬盘为/dev/sdb

<span style="font-size:12px;">[root@localhost ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x14c853e7.
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 4 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):
</span>

输入m后会查看这些命令的介绍

<span style="font-size:12px;">Command (m for help): m
Command action
   a   toggle a bootable flag                  // 设置可引导标记
   b   edit bsd disklabel                      // 编辑bsd磁盘标签
   c   toggle the dos compatibility flag       // 设置DOS操作系统兼容标记
   d   delete a partition                      // 删除一个分区
   l   list known partition types              // 显示已知的文件系统类型
   m   print this menu                         // 显示帮助菜单
   n   add a new partition                     // 新建分区
   o   create a new empty DOS partition table   // 建立空白DOS分区表
   p   print the partition table                // 显示分区列表
   q   quit without saving changes              // 不保存退出
   s   create a new empty Sun disklabel         // 新建空白SUN磁盘标签
   t   change a partition's system id           // 改变一个分区的系统ID
   u   change display/entry units               // 改变显示记录单位
   v   verify the partition table               // 验证分区表
   w   write table to disk and exit             // 保存退出
   x   extra functionality (experts only)       // 附加功能

Command (m for help):
</span>

（2）新建主分区，输入n开始新建分区

<span style="font-size:12px;">Command (m for help): n
Command action
   e   extended                                // 扩展分区
   p   primary partition (1-4)                 // 主分区
p                                              // 先新建一个主分区
Partition number (1-4): 1                      // 输入主分区的分区号
First cylinder (1-72937, default 1):          // 默认从第一个磁柱开始
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-72937, default 72937): +300G
// 在此输入最后一个磁柱，表示此分区的大小，这里需要大家自己换算一个空间大小，但Linux提供了更加人性化的表示方式，可以直接输入空间大小+300G
</span>

（3）新建扩展分区，再次输入n新建

<span style="font-size:12px;">Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
e                                               // 新建扩展分区
Partition number (1-4): 2                       // 分区号
First cylinder (39164-72937, default 39164):    // 默认即可
Using default value 39164
Last cylinder, +cylinders or +size{K,M,G} (39164-72937, default 72937): 
// 若把剩余的空间全部分给扩展分区，默认即可，若只利用其一部分，按上述的步骤操作
Using default value 72937
</span>

（4）查看分区情况，输入p

<span style="font-size:12px;">Command (m for help): p

Disk /dev/sdb: 599.9 GB, 599932844032 bytes
255 heads, 63 sectors/track, 72937 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 524288 bytes
Disk identifier: 0x14c853e7

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       39164   314584544+  83  Linux
Partition 1 does not start on physical sector boundary.
/dev/sdb2           39164       72937   271281876+   5  Extended
</span>

（5）新建逻辑分区

<span style="font-size:12px;">Command (m for help): n
Command action
   l   logical (5 or over)                      // 逻辑分区
   p   primary partition (1-4)
l                                               // 新建逻辑分区
First cylinder (39164-72937, default 39165):    // 从扩展分区中划分逻辑分区
Using default value 39165
Last cylinder, +cylinders or +size{K,M,G} (39165-72937, default 72937): 
Using default value 72937
</span>

再次查看可知：

<span style="font-size:12px;">Command (m for help): p

Disk /dev/sdb: 599.9 GB, 599932844032 bytes
255 heads, 63 sectors/track, 72937 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 262144 bytes / 524288 bytes
Disk identifier: 0x14c853e7

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       39164   314584544+  83  Linux
Partition 1 does not start on physical sector boundary.
/dev/sdb2           39164       72937   271281876+   5  Extended
/dev/sdb5           39165       72937   271281622+  83  Linux
Partition 5 does not start on physical sector boundary.
</span>

由上述信息可知，逻辑分区的分区号是从5开始的，这是因为主分区+扩展分区最多只能分4个，而逻辑分区可以分若干个，SCSI最多可分16个逻辑分区，IDE最多分63个分区。

输入w保存退出

<span style="font-size:12px;">Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.</span>

3 格式化

3.1 格式化主分区

建立好分区之后，要对其进行格式化操作。

<span style="font-size:12px;">[root@localhost ~]# mkfs -t ext4 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
/dev/sdb1 alignment is offset by 229888 bytes.
This may result in very poor performance, (re)-partitioning suggested.
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=64 blocks, Stripe width=128 blocks
19668992 inodes, 78646136 blocks
3932306 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
2401 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000, 7962624, 11239424, 20480000, 23887872, 71663616

Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: 
done

This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.</span>

3.2 格式化扩展分区

主分区已格式化完成，接下来格式化扩展分区

[root@localhost ~]# mkfs -t ext4 /dev/sdb2
mke2fs 1.41.12 (17-May-2010)
mkfs.ext4: inode_size (128) * inodes_count (0) too big for a
	filesystem with 0 blocks, specify higher inode_ratio (-i)
	or lower inode count (-N).

结果显示出现错误，这是因为直接格式化扩展分区是不允许的，只能格式化主分区和逻辑分区。

3.3 格式化逻辑分区

[root@localhost ~]# mkfs -t ext4 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
/dev/sdb5 alignment is offset by 2048 bytes.
This may result in very poor performance, (re)-partitioning suggested.
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=64 blocks, Stripe width=128 blocks
16957440 inodes, 67820405 blocks
3391020 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
2070 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000, 7962624, 11239424, 20480000, 23887872

Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: 
done

This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

 

4 挂载

4.1 临时挂载

先建立两个空目录，作为挂载点

 

[root@localhost ~]# mkdir /disk1
[root@localhost ~]# mkdir /home/disk5

挂载

[root@localhost ~]# mount /dev/sdb1 /disk1
[root@localhost ~]# mount /dev/sdb5 /home/disk5

查看

[root@localhost ~]# mount
/dev/mapper/VolGroup-lv_root on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
/dev/mapper/VolGroup-lv_home on /home type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
<span style="color:#ff0000;">/dev/sdb1 on /disk1 type ext4 (rw)
/dev/sdb5 on /home/disk5 type ext4 (rw)</span>

挂载成功！

4.2 永久挂载

查看分区的UUID

[root@localhost ~]# blkid
/dev/sda1: UUID="c52896c1-468e-49a1-a57a-5c4dd643230c" TYPE="ext4" 
/dev/sda2: UUID="t8tBtG-4gaK-8OQH-lHdO-qUUt-OHE8-rrJb8B" TYPE="LVM2_member" 
/dev/mapper/VolGroup-lv_root: UUID="0ea03348-489d-4e85-a6c9-dba25dc9bfa4" TYPE="ext4" 
/dev/mapper/VolGroup-lv_swap: UUID="06dcde24-f621-4e07-9846-1a2be5d3025d" TYPE="swap" 
/dev/mapper/VolGroup-lv_home: UUID="507c118a-e085-4d05-b349-d8a9f10b861c" TYPE="ext4" 
<span style="color:#ff0000;">/dev/sdb1: UUID="de95793a-c343-464b-a799-373ab1d9eb18" TYPE="ext4" 
/dev/sdb5: UUID="548429b6-d343-4049-8775-0fb46c71945d" TYPE="ext4"
</span>

修改/etc/fstab文件

[root@localhost ~]# vi /etc/fstab 
#
# /etc/fstab
# Created by anaconda on Thu Apr 14 05:59:56 2016
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/VolGroup-lv_root /                  ext4    defaults        1 1
UUID=c52896c1-468e-49a1-a57a-5c4dd643230c /boot   ext4   defaults       1 2
/dev/mapper/VolGroup-lv_home /home              ext4    defaults        1 2
/dev/mapper/VolGroup-lv_swap swap               swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
<span style="color:#ff0000;">UUID=de95793a-c343-464b-a799-373ab1d9eb18 /disk1     ext4   defaults    1 2
UUID=548429b6-d343-4049-8775-0fb46c71945d  /home/disk5  ext4   defaults 1 2</span>

因为fstab是系统启动的一个重要文件，所以我们要用mount -a来查看，若没有报错，则说明配置正确。

[root@localhost ~]# mount -a

再次查看确认

 

[root@localhost ~]# df -Th
Filesystem                   Type   Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root ext4    50G  769M   46G   2% /
tmpfs                        tmpfs   32G     0   32G   0% /dev/shm
/dev/sda1                    ext4   485M   33M  427M   8% /boot
/dev/mapper/VolGroup-lv_home ext4   198G  188M  188G   1% /home
<span style="color:#ff0000;">/dev/sdb1                    ext4   296G  191M  281G   1% /disk1
/dev/sdb5                    ext4   255G  188M  242G   1% /home/disk5</span>

5 注意事项

若fstab文件写错，则在开机启动时会报错，这时就不能远程对其进行操作，需要在本机上对fstab文件进行修改，但用vi/vim是编辑不了文件，这时候需要输入

[root@localhost~]# mount -o remount,rw /

此时就可以再次修改fstab这个文件了。