linux 磁盘挂载

1、磁盘的格式化

1.1、查看当前文件目录

使用 df -h 命令来查看当前已经挂载的磁盘以及磁盘的信息:

    root:~>df -h
    文件系统        容量  已用  可用 已用% 挂载点
    /dev/sda3       259G  229G   30G   89% /
    devtmpfs         32G     0   32G    0% /dev
    tmpfs            32G   16M   32G    1% /dev/shm
    tmpfs            32G  3.2G   29G   11% /run
    tmpfs            32G     0   32G    0% /sys/fs/cgroup
    /dev/sda1       497M  191M  306M   39% /boot
    tmpfs           6.3G     0  6.3G    0% /run/user/0
    cm_processes     32G  2.7G   29G    9% /run/cloudera-scm-agent/process
    tmpfs           6.3G   12K  6.3G    1% /run/user/42

1.2、磁盘分区

  • 查找已经安装并且未格式化的磁盘
    使用命令 fdisk -l 列出所有的磁盘,使用命令的例子以及结果如下:
    root:~>fdisk -l
    磁盘 /dev/sda:299.4 GB, 299439751168 字节,584843264 个扇区
    Units = 扇区 of 1 * 512 = 512 bytes
    扇区大小(逻辑/物理):512 字节 / 512 字节
    I/O 大小(最小/最佳):512 字节 / 512 字节
    磁盘标签类型:dos
    磁盘标识符:0x000de8f6
       设备 Boot      Start         End      Blocks   Id  System
    /dev/sda1   *        2048     1026047      512000   83  Linux
    /dev/sda2         1026048    42969087    20971520   82  Linux swap / Solaris
    /dev/sda3        42969088   584843263   270937088   83  Linux
    磁盘 /dev/sdb:3000.0 GB, 3000034656256 字节,5859442688 个扇区
    Units = 扇区 of 1 * 512 = 512 bytes
    扇区大小(逻辑/物理):512 字节 / 512 字节
    I/O 大小(最小/最佳):512 字节 / 512 字节
    磁盘标签类型:gpt
    Disk identifier: 69D07AFC-584D-4926-81B8-8DEF8087445F

可以看出 /dev.sdb 还没有格式化以及挂载。

  • 格式化磁盘
    在 CentOS 7.0 以后 fdisk 也支持了大磁盘的格式话。本文章是再 CentOS 7.4 上进行的。
    使用 fdisk /dev/sdb 根据帮助提示分区,这里是把 /dev/sdb 分成一个区.
    [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 0x0adfd119.
    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): m
    Command action
       a   toggle a bootable flag
       b   edit bsd disklabel
       c   toggle the dos compatibility flag
       d   delete a partition
       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)
    Command (m for help): n
    Command action
       e   extended
       p   primary partition (1-4)
    p
    Partition number (1-4): 1
    First cylinder (1-6527, default 1): 
    Using default value 1
    Last cylinder,  cylinders or  size{K,M,G} (1-6527, default 6527): 
    Using default value 6527
    Command (m for help): p
    Disk /dev/sdb: 53.7 GB, 3000034656256 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): 512 bytes / 512 bytes
    Disk identifier: 0x69D07AFC-584D-4926-81B8-8DEF8087445F
        Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1               1        6527    5859442688   83  Linux
    Command (m for help): w
    The partition table has been altered!
    Calling ioctl() to re-read partition table.
    Syncing disks.
  • 格式化磁盘

命令 mkfs.ext4 /dev/sdb1 分区为 ext4 的文件系统格式。

    [root@localhost ~]# mkfs.ext4 /dev/sdb1 
    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
    3276800 inodes, 13107024 blocks
    655351 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=4294967296
    400 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
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done
    This filesystem will be automatically checked every 28 mounts or
    180 days, whichever comes first.  Use tune2fs -c or -i to override.

2、挂载磁盘

2.1、手动挂载

手动挂载每次重启都需要执行一次,比较麻烦:

手动挂载步骤:

  • 准备挂载的目录:
    mkdir /home/data
    chmod 777 /home/data
  • 使用 mount 命令挂载
    mount /dev/sdb1 /home/data

2.2、自动挂载

自动挂载不需要重启后在执行,推荐使用:

自动挂载的步骤为:

  • 准备挂载的目录:
    mkdir /home/data
    chmod 777 /home/data
  • 挂载步骤:
  1. fdisk -l
  2. 找到要挂载的磁盘(举例/dev/sdb)
  3. 查看磁盘文件
    vim /ext/fstab
    \# /etc/fstab
    \# Created by anaconda on Tue Jul  4 05:46:31 2017
    \# 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/cl-root     /                       xfs     defaults        0 0
    UUID=619a7a33-84ff-4b7f-befd-c798c04f68a4 /boot                   xfs     defaults        0 0
    /dev/mapper/cl-swap     swap                    swap    defaults        0 0
  1. 添加新挂载的硬盘
    /dev/sdc        /home/data     ext4    defaults        0 0

参数说明:

  • 第一列:实际的分区名,也可以是实际的分区的卷标;
  • 第二列:挂载点,最好文件夹已存在并且权限为 777;
  • 第三列:此分区文件系统类型;
  • 第四列:挂载的选项,用于设置挂载的参数。
    常见参数如下:    
      auto 系统自动挂载,默认选项;
      defaults  rw,suid,dev,exec,auto,nouser,ansyc;
      noauto   开机不自动挂载;
      nouser    只有超级用户可以挂载;
      ro    按照只读权限挂载;
      rw    按照可读可写权限挂载;
      user    任何用户都可以挂载。
  • 第五列:dump备份设置
    • 1 允许 dump 备份程序备份;
    • 0 忽略备份操作;
  • 第六列:fsck 磁盘检查设置
    • 0 永不检查
    • 目录永远为 1
    • 其他分区从 2 开始,数字越小越先检查。

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