Ubuntu under U disk read-only

question

Sometimes insert a U disk under ubuntu, and find that the content cannot be modified. For example, you cannot create new files and folders, and you cannot copy files to the U disk. The system prompts: read-only file system.
The reason is probably that the file system information of the U disk is wrong (saved in the front of a hard disk or U disk, which has all the file information).
Formatting the USB drive will naturally solve the problem, but it will delete all data on the USB drive.
To repair the U disk without deleting the files, you can use the following methods.

Solution

1 View U disk information

First insert the USB stick.
Open the command line and execute the following commands:

df -h

Use if you have insufficient permissions sudo.
Display the information of all mounted hard disk U disks, for example:

文件系统        容量  已用  可用 已用% 挂载点
udev            3.9G     0  3.9G    0% /dev
tmpfs           786M  9.6M  776M    2% /run
/dev/sda5       272G  137G  121G   54% /
tmpfs           3.9G  208M  3.7G    6% /dev/shm
tmpfs           5.0M  4.0K  5.0M    1% /run/lock
tmpfs           3.9G     0  3.9G    0% /sys/fs/cgroup
tmpfs           786M   92K  786M    1% /run/user/1000
/dev/sdb1       284G  217G   68G   77% /media/admin/MyUDisk

As you can see, the file system of the U disk is /dev/sdb1, and the mount point is /media/admin/MyUDisk.

2 Uninstall the U disk

sudo umount /media/admin/MyUDisk

Do not unplug the U disk after uninstalling!

3 Repair U disk file system failure

sudo dosfsck -v -a /dev/sdb1

Note: This is /dev/sdb1just an example, please refer to the actual situation!
The execution time of this command is variable, it may complete quickly, or it may take a few minutes, please be patient.

Re-mount the U disk to check whether it has been repaired.