Can't change ownership of file, even using sudo

mstrimel · 09-17-2022, 05:06 PM

Hello,
I have an external USB drive on which I created a exFAT partition. I mounted it at /media/filestogo and after chmod'ing that directory to 777. When I try to copy files to that directory in Nautilus, I get the error that I do not have permission. So, I tried to chown the directory /media/filestogo to user mary. However I get an error:

Code:

mary@mythbox:~]$ ls -la /media/filestogo
total 132
drwxr-xr-x. 2 root root 131072 Sep 17 17:52 .
drwxr-xr-x. 9 root mary   4096 Sep 17 17:50 ..
[Sat Sep 17 18:05:12]
mary@mythbox:~]$ sudo chown mary /media/filestogo
chown: changing ownership of '/media/filestogo': Operation not permitted
[Sat Sep 17 18:05:22]

What am I doing wrong? I checked the mount options of the USB drive and it is mounted rw.
Thanks,
Mary

Emerson · 09-17-2022, 05:17 PM

I'd suspect exFAT does not support UNIX style permissions and ownership. Perhaps you can mount it as user mary, then ownership should change, methinks.

rkelsen · 09-17-2022, 05:19 PM

What options did you use in your mount command?

mstrimel · 09-17-2022, 06:42 PM

Quote:

Originally Posted by Emerson

I'd suspect exFAT does not support UNIX style permissions and ownership. Perhaps you can mount it as user mary, then ownership should change, methinks.

Thank you, that was the solution. I changed the /etc/fstab file to specify "user" as an option.

frankbell · 09-17-2022, 09:05 PM

Just as an aside, Emerson is correct. Non-*nix filesystems do not recognize/support Linux permissions.

Emerson · 09-17-2022, 09:19 PM

I haven't used non-nix filesystems for so long (15+ years) I really wasn't sure what is the best way to solve this and I had nothing to try it on.

frankbell · 09-17-2022, 09:42 PM

It's something I learned along the way, but so long ago I can't cite a source.

ferrari · 09-17-2022, 11:44 PM

FAT/exFAT and NTFS (Microsoft) file systems don't support Linux user and group permissions. These are essentially faked by the kernel when mounted.

For more info refer

Code:

man mount.exfat

https://www.systutorials.com/docs/li...8-mount.exfat/

Code:

man mount.ntfs

https://www.systutorials.com/docs/li.../8-mount.ntfs/

shevegen · 09-25-2022, 08:25 AM

Interesting - I never knew about mount.exfat. This may
explain similar errors I got in the past.

I found the thread here via a google search.

Would be great if the whole Linux stack would be more
"clever"; would help avoid me having to google, with
a better "live" documentation system as-is.

Emerson · 09-25-2022, 09:48 AM

'mount' command calls 'mount.<filesystem>', you will be using mount.exfat when you mount exfat filesystem.