CentOS7下挂载新磁盘
山小杰
2月 02, 2018
虚拟机也好，物理机也罢，在CentOS的使用过程中都有可能会出现需要增加磁盘的情况，这篇文章就是介绍如何为新磁盘进行分区以及挂载操作。
所有操作都在root用户下进行。
查看当前磁盘使用状况
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/cl-root 18G 15G 3.3G 82% /
devtmpfs 902M 0 902M 0% /dev
tmpfs 912M 0 912M 0% /dev/shm
tmpfs 912M 8.6M 904M 1% /run
tmpfs 912M 0 912M 0% /sys/fs/cgroup
/dev/sda1 197M 119M 79M 61% /boot
tmpfs 183M 0 183M 0% /run/user/0
列出现有的磁盘及分区信息
# fdisk -l
# /dev/sda 是原有的磁盘，可以看到这块磁盘下面的分区信息
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 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: 0x000b4958
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 411647 204800 83 Linux
/dev/sda2 411648 41943039 20765696 8e Linux LVM
/dev/sda3 41943040 83886079 20971520 83 Linux
# /dev/sdb 就是我们刚添加的磁盘（如果原来只有一块磁盘的话），可以看到这块磁盘下面没有任何分区
Disk /dev/sdb: 42.9 GB, 42949672960 bytes, 83886080 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 /dev/mapper/cl-root: 19.1 GB, 19113443328 bytes, 37330944 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 /dev/mapper/cl-swap: 2147 MB, 2147483648 bytes, 4194304 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
对新磁盘 /dev/sdb 进行分区操作
# 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 0xfd5ee39c.
# 输入 m 可以查看命令帮助（我们只需要用到 n 和 w 两个命令）
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 # 添加分区
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 # 写入分区表并退出
x extra functionality (experts only)
# 输入 n 添加分区（一块磁盘最多可以有4个主分区-primary，没有特殊需求的话，全部按默认分一个区就行）
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
Partition number (1-4, default 1):
First sector (2048-83886079, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-83886079, default 83886079):
Using default value 83886079
Partition 1 of type Linux and of size 40 GiB is set
# 输入 w 保存分区信息
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
再次查看磁盘分区信息
# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 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: 0x000b4958
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 411647 204800 83 Linux
/dev/sda2 411648 41943039 20765696 8e Linux LVM
/dev/sda3 41943040 83886079 20971520 83 Linux
Disk /dev/sdb: 42.9 GB, 42949672960 bytes, 83886080 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: 0xfd5ee39c
# 可以看到刚刚分的一个区 /dev/sdb1
Device Boot Start End Blocks Id System
/dev/sdb1 2048 83886079 41942016 83 Linux
Disk /dev/mapper/cl-root: 19.1 GB, 19113443328 bytes, 37330944 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 /dev/mapper/cl-swap: 2147 MB, 2147483648 bytes, 4194304 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
格式化新分区 /dev/sdb1
这里使用ext4文件系统# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
2621440 inodes, 10485504 blocks
524275 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2157969408
320 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
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
创建分区挂载目录
# mkdir /mnt/disk01
挂载新分区
# mount /dev/sdb1 /mnt/disk01/
查看磁盘使用情况
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/cl-root 18G 15G 3.3G 82% /
devtmpfs 902M 0 902M 0% /dev
tmpfs 912M 0 912M 0% /dev/shm
tmpfs 912M 8.6M 904M 1% /run
tmpfs 912M 0 912M 0% /sys/fs/cgroup
/dev/sda1 197M 119M 79M 61% /boot
tmpfs 183M 0 183M 0% /run/user/0
# 多出来了这个
/dev/sdb1 40G 49M 38G 1% /mnt/disk01
设置开机自动挂载磁盘
# vim /etc/fstab
/dev/sdb1 /mnt/disk01 ext4 defaults 0 0
说明:
第一列是设备名
第二列是挂载点（挂载目录）
第三列是要使用的文件系统
第四列是挂载参数，使用默认即可（defaults）
第五列是dump备份参数，1：每天备份，2：不定期备份，0：不备份
第六列是扇区检验参数，1：最早检验，2：标识为1的设备检验完之后检验，0：不检验