pen drive unmounts and remounts as readonly

Question

When I plug in my USB pen drive, it is automatically mounted as read/write, as expected.

However, after a random time it suddenly gets unmounted and remounted as read-only.

A part from waiting for this annoying bug to be fixed, is there a workaround to prevent this from happening?

Answer 1

open terminal and type dmesg & insert your pen drive and check the Log of it .dmesg contains the system log .

for more info , look at here https://help.ubuntu.com/community/Mount/USB#Device_become_suddenly_read_only

Answer 2

To expand on raja.genupula's answer, this could mean you need to do a filesystem check on the drive.

Try this, open up Terminal, type dmesg, then insert your pen drive and wait for it to become read-only. dmesg shows you system log messages, and if you see any like this after it becomes read-only:

[17183798.908000] FAT: Filesystem panic (dev sda1)
[17183798.908000]     fat_get_cluster: invalid cluster chain (i_pos 0)
[17183798.908000]     File system has been set read-only

Then it likely indicates that you need to do a filesystem check. To check the filesystem, use "Disk Utility" (under System, Administration), find your device, unmount it, check the file system, then mount it again.

Source: https://help.ubuntu.com/community/Mount/USB#Device_become_suddenly_read_only