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i9pp0
Asked: 2020-12-21 06:30:53 +0800 CST

Why does USB stick keep becoming read only?

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I have a 64GB stick that was working fine. I started putting movies on it, and then suddenly, one day it becomes read only. chmod cannot change it. So I reformatted and started again. After 2 days it became read only again for no apparent reason. I reformatted again (FAT32 each time) because I have to plug it into a player that can't read ext4. And again it became read only. So it works for a couple of days after reformatting, then becomes read only.

Any ideas as to why this is happening?

boot partitioning usb

2 Answers

  1. Best Answer

    A file system that is mounted read-only may not be clean, i.e. properly closed. It then is in an inconsistent state. Have the file system checked, after which it should mount without problems. You can check and repair a file system using the "Disks" utility included with Ubuntu. You can check a file system only when it is not mounted, so unmount first. The tool to check a file system at the command line is fsck.

    To prevent this from happening again, always make sure to carefully eject the drive using software before physically unplugging it. The system will give you a notification when it is safe to remove the drive. Before that, it may give you a notification that it is not yet safe, if data still needs to be committed to disk.

    If you carefully remove a drive, the file system will remain healthy for a longer time. It still is a good idea to check the file system of any removable drive from time to time. File systems on your internal drives that are used by the system are checked automatically on every reboot.

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  2. It is possible the drive is getting worn out. Flash storage has only so many write cycles before it cannot be written to again. Magnetic storage, as used in hard disk storage as opposed to solid state, does not have this limit. Hard drives have other parts that will wear so they have limited lives too. USB storage is not built to be as durable as the kind of solid state storage used in a SATA drive, that’s how they make them at lower cost. Reformatting the drive only increases this wear. The means to check on the wear status of a drive will vary based on manufacturer and specific technology used. If chmod will not fix the read only issue then that is evidence of a hardware vs software problem.

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