USB drives suddenly forced read-only - SOLVED

[Bob Unitt]

I'm running Mint 17.3/Cinnamon. I have a number of USB sticks I've used in the past which have suddenly become 'read only' on this PC. Any attempt to change their properties to 'read/write' is ignored, even when in 'sudo nemo' mode. I've checked these USB sticks on a couple of other linux PC's and they're read-write and full access on those, so it's definitely the PC and not the USB sticks. The only unusual thing I've done with them recently is to reformat one from being a bootable ISO to an ordinary file-system. Any suggestions ?

P.S. I know Mint 17.3 is obsolete so I'm trying to upgrade to 20.1, which is why i need working USB sticks.

[AndyMH]

The only unusual thing I've done with them recently is to reformat one from being a bootable ISO to an ordinary file-system

I find sometimes that a stick that has an iso on it does not easily reformat to a standard filesystem.

The simplest solution is to install mkusb:
https://help.ubuntu.com/community/mkusb
it has a 'restore to standard storage device' option.

Or you could wipe the first MB of the stick with dd, add a new partition table and a new partition(s) - which is what mkusb does for you.

[Bob Unitt]

The problem isn't the USB stick - *all* my USB sticks now show as being read-only on this particular PC.

[AndyMH]

*all* my USB sticks now show as being read-only on this particular PC.

Including ones you haven't burnt an iso to?

[Bob Unitt]

Yes.

The odd thing is that it only affects USB sticks, I have an external hard-disk which connects via USB, and I can write to that with no problem.

[Bob Unitt]

Thanks AndyMH. I've been doing some googling. I found this thread https://askubuntu.com/questions/563764/ ... -read-only which suggested trying a 'killall nautilus ' command. I entered 'killall nemo' instead, and then rebooted. At first I got a couple of odd error messages, but those seemed to clear themselves and I can now write to my USB sticks OK.

This problem has been around for a long time - first reported in 2012 on 12.04, and still present in 2021 on 20.1. See:
https://bugs.launchpad.net/ubuntu/+sour ... ug/1021375
and
https://bugzilla.redhat.com/show_bug.cgi?id=844713 where the status was set to 'CLOSED WONTFIX' in 2015.

[AndyMH]

I had a different issue in a custom iso I'd built and using thunar as the file manager. Sometimes it wouldn't open other partitions. I fixed it with a short script

Code: Select all

systemctl --user restart gvfs-udisks2-volume-monitor
thunar 

when you have a usb stick read-only try restarting udisks2 as above and see if it fixes it. No guarantees...

[Bob Unitt]

Is 'thunar' a separate command, or just a word-wrap on a single line command ?

[AndyMH]

thunar is the file manager installed by default in xfce, i.e. restart gvfs-udisks2 then run thunar. If running cinnamon, it would be nemo. Mate is caja. But I suggest, when you have an issue with a stick, restart gvfs-udisks2 from a terminal and then open your file manager as normal. As I said before, no guarantees it will work, but worth trying.

[Bob Unitt]

Gotcha - thanks.

[Old Mintbear]

I am another relative newbee who has had this problem of all the folders and files on my external hard drive suddenly becoming "READ ONLY". I've looked through the suggestions above and have been summoning up the courage to try them, as I'm still getting used to using the terminal. Curiosity made wonder if another computer which was still running Windows could access and alter the files . . . . or would it get the same "Read Only" message.

I plugged the drive into a laptop running Windows 7 and immediately a panel appeared saying . . . . "Do you want to scan and fix FREECOM HDD (E:)? . . . . There might be a problem with some files on this device or disc. This can happen if you remove the device or disc before all files have been written to it." The two options were: "Scan and fix (recommended) this will prevent future problems when copying files to this device or disc" OR "Continue without scanning". Realising there were problems I clicked on the Scan and fix option. After a bit of whirring from the drive it was done. I looked at the files and everything was OK . . . . . but was this just when accessing them from a computer using Windows 7?

So I unplugged the external hard drive and plugged it back into my desktop running Linux Mint Cinnamon. Surprise, surprise . . . everything was now back to normal! I altered a document just to make sure but it was fine. I offer this as a possible solution for users like myself who are new to Linux and may find this method both easier and a bit less daunting.

[AndyMH]

To con the users that win10 is quicker than it is, it has a feature called fast start (enabled by default). It never really shuts down (= appears quicker to boot up from cold). A side effect is that it leaves any windows filesystems that it has had access to locked and thus read-only to linux. If running win10 the solution is to turn of fast start, or as you found win7 fixed the problem.