Linux：解决U盘可以识别，但在/dev目录下只有sda，却无设备节点(sda1)的问题

缺乏、安全感 2022-03-15 11:12 1887阅读 0赞

> **问题：U盘接入，系统可以识别，但在/dev目录下只有sda（或其他），却无设备节点sda1（或其他）？**

**解决：**

（1）查看U盘是否分区

#fdisk /dev/sda                              /*进入fdisk命令操作空间*/
    #Command (m for help): m                     /*命令查看*/
    Command action
    a   toggle a bootable flag                   #设置引导扇区
    b   edit bsd disklabel                       #编辑卷标（linux下使用的卷标bsd通用）
    c   toggle the dos compatibility flag
    d   delete a partition                       #删除分区 
    l   list known partition types               #列出已知的分区类型 
    m   print this menu       
    n   add a new partition                      #添加一个新的分区 
    o   create a new empty DOS partition table   #生成一个新的空DOS分区列表 
    p   print the partition table                #打印分区列表 
    q   quit without saving changes              #不保存退出
    s   create a new empty Sun disklabel
    t   change a partition's system id           #改变一个分区列表的ID 
    u   change display/entry units
    v   verify the partition table
    w   write table to disk and exit             #写入列表到磁盘并退出
    x   extra functionality (experts only)
    
    #Command (m for help): p
    
    Disk /dev/sda: 8178 MB, 8178892800 bytes
    252 heads, 62 sectors/track, 1022 cylinders
    Units = cylinders of 15624 * 512 = 7999488 bytes
    
       Device Boot      Start         End      Blocks  Id System  /*可见U盘无分区*/

（2）若未分区，创建分区sda1，并格式化（也可以不进行格式化）

#fdisk /dev/sda                                                                                                 
    
    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
    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                        /*n表示添加一个新的分区*/
    Command action
       e   extended                                /*创建扩展分区*/
       p   primary partition (1-4)                 /*创建主分区*/
    p                                              
    Partition number (1-4): 1                      /*输入主分区号，这里设置为1*/
    First cylinder (1-1022, default 1): Using default value 1 /*起始，回车使用默认值*/
    Last cylinder or +size or +sizeM or +sizeK (1-1022, default 1022): Using default  value 1022 /*结尾，回车使用默认值*/
    
    Command (m for help): p                        /*p表示打印分区列表*/                                                                    
    
    Disk /dev/sda: 8178 MB, 8178892800 bytes
    252 heads, 62 sectors/track, 1022 cylinders
    Units = cylinders of 15624 * 512 = 7999488 bytes
    
       Device Boot      Start         End      Blocks  Id System  /*可见sda1分区已创建*/
    /dev/sda1               1        1022     7983833  83 Linux
    
    Command (m for help): w
    The partition table has been altered.
    Calling ioctl() to re-read partition table
    
    #mkfs -t vfat /dev/sda1                        /*对sda1进行格式化（也可以不进行这一步）*/
    mkfs.vfat 3.0.12 (29 Oct 2011)
    mkfs.vfat: /dev/sda1 contains a mounted file system.
    
    #fsck -t vfat /dev/sda                         /*格式化完成后对U盘进行修复*/
    fsck from util-linux 2.20.1
    dosfsck 3.0.12, 29 Oct 2011, FAT32, LFN
    Logical sector size (64543 bytes) is not a multiple of the physical sector size.

（3）前两步完成后，在/dev目录下将会出现设备节点sda1；如果没有，则手动创建设备节点sda1

#mknod /dev/sda1 b 8 1                /*手动创建设备节点sda1*/
    #mount /dev/sda1 /mnt/udisk           /*挂载U盘到/mnt/udisk目录下*/
    #umount /mnt/udisk                    /*卸载U盘*/