Unable to write to thumb drive

[WanderingOak]

I have a relatively new install of Buster. Recently, I have had problems working with thumb drives. I can read from a thumb drive fine. However, when I try to copy files to the thumb drive, I am given an error message saying "Read-only file system". The thumb drive is formatted Fat 32 for transferring files from my Debian laptop to a Mac. I am using LXQT 0.14.1.

My /etc/fstab reads as follows:
/dev/mapper/debian--vg-root / ext4 errors=remount-ro 0 1
# /boot was on /dev/sda2 during installation
UUID=0413573b-19af-4486-b0bb-87ca167eea69 /boot ext2 defaults $
# /boot/efi was on /dev/sda1 during installation
UUID=B99A-50C8 /boot/efi vfat umask=0077 0 1
/dev/mapper/debian--vg-swap_1 none swap sw 0 0
/dev/sr0 /media/cdrom0 udf,iso9660 user,noauto 0 0

The thumb drive is mounted, and I can read it in pamanfm-qt .

If I navigate to it's location (/media/username/ ) ls-l shows drwxrwxr-x 1 root root
I tried running chmod 777 as root, but was unable to change anything. Using cp -r as root resulted in: "cannot create directory 'directory': Read-only file system".

Any assistance would be appreciated.

[Loci.Cantos]

Owner and Group appear to have read write execute on the usb media.
Your users don't have write privileges.
"who" is trying to write to the media? I don't know your instantiation as a file system operator (appears to be root).
Also, how much space is available on the media?

However, this may be useful...
https://www.linux.com/training-tutorial ... rmissions/

[sgosnell]

I've seen that happen with failed USB drives. They do fail. I futzed with one for a very long time before tossing it in the round file. I suspected that it was bad all along, but I kept working at it just for the education. At the price for them now, it's not really worth expending much effort. Have you tried different drives with the computer?

[stevepusser]

If it's bad, usually dmesg in the terminal will show errors after it's inserted. It's been mounted read-only so you can recover data before trying to repair it.

[Bulkley]

It's an ownership problem. When you do ls-l you get drwxrwxr-x 1 root root. When I do it I get drwxrwxr-x 1 [my username] [my username].

[WanderingOak]

I've seen that happen with failed USB drives. They do fail. I futzed with one for a very long time before tossing it in the round file. I suspected that it was bad all along, but I kept working at it just for the education. At the price for them now, it's not really worth expending much effort. Have you tried different drives with the computer?

Whelp, I figured out what the problem was. I ran mount | grep "^/dev", and it turns out that the thumb drive was formatted HFS+. I forgot that I had a thumb drive or two formatted that way for transferring large video files from one Mac to another. I need to label them 'Mac only' so I don't use them on my *nix boxes. Thanks everybody for all of the responses.

[stevepusser]

I wonder if dmesg can detect that problem, or if you just get a generic error.

[p.H]

Linux can write on an HFS+ filesystem if it is not marked as journalled. Otherwise it will be mounted read-only by default.

AFAIK Debian has no tool to disable the journal on an existing HFS+ filesystem. However you can mount a journalled HFS+ filesystem read-write with the "force" mount option (at your own risks).

mkfs.hfsplus from package hfsprogs has an option to create an HFS+ filesystem with or without a journal.