Talk:USB storage devices

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device descriptor read error

Some USB controllers will be loaded with the wrong USB standard applied (e.g. a USB 3.0 controller is initialized with a USB 2.0 kernel module assigned) causing a loss of performance and an error message that looks something like "device descriptor read/64, error -32" at boot time. A supposed fix I found involves issuing the following command as root: "echo -1 >/sys/module/usbcore/parameters/autosuspend". Since I don't have a USB storage device handy it's hard for me to verify that the performance impact was fixed, but I can verify that this at least supressed the error message. This also does not specifically pertain to USB storage devices, but there is not a wiki page specifically for general USB controller usage and I didn't find it in order to create one just to add a single troubleshooting step. Mynis (talk) 21:24, 14 December 2013 (UTC)

Mount ext4-formatted usb drive so it can be written by the user

Does USB storage devices#As normal user with mount work? When trying to use these option I get errors. I think extra steps, like 'chown'ing the directory, are needed. -- Karol (talk) 02:32, 18 November 2014 (UTC)

It works fine for me, the ownership of the mountpoint is set according to the gid= argument and its permission according to fmask= and dmask= - exactly the same as for the other files on the mounted drive. I.e., I get the following:
# mount -o gid=lahwaacz,fmask=113,dmask=002 /dev/sdb1 /mnt/
$ ll /mnt/
total 863M
drwxrwxr-x 14 root lahwaacz 8.0K Jan  1  1970 ./
drwxr-xr-x 18 root root     4.0K Nov  7 19:35 ../
drwxrwxr-x  2 root lahwaacz 8.0K Jun 21 12:25 app/
drwxrwxr-x  5 root lahwaacz 8.0K Sep 13 10:03 boot/
...
$ touch foo
$ ll /mnt/
total 863M
drwxrwxr-x 14 root lahwaacz 8.0K Dec  6 23:00 ./
drwxr-xr-x 18 root root     4.0K Nov  7 19:35 ../
drwxrwxr-x  2 root lahwaacz 8.0K Jun 21 12:25 app/
drwxrwxr-x  5 root lahwaacz 8.0K Sep 13 10:03 boot/
-rw-rw-r--  1 root lahwaacz    0 Dec  6 23:00 foo
...
What kind of errors do you get?
Edit: dumb me, I should have read the title first... I have tried it with a NTFS drive, not with ext4. The problem is likely in the gid= mount option, which is not filesystem independent (see mount(8)). In fact, it makes sense only on filesystems not storing Linux file permissions.
-- Lahwaacz (talk) 22:17, 6 December 2014 (UTC)

Inform users that ntfs-3g is required to be able to write to NTFS devices

Following USB storage devices#As normal user with mount, I was unable to write to my NTFS formatted hard drive. Any attempts at writing resulted in a message stating that this device was read-only. It took some looking around to find out that Arch doesn't ship with ntfs-3g installed and having this information listed in this page would definitely be handy. It is true that this information is provided in the File systems page but is that really reason to not mention it here as well? If not as an addition to the troubleshooting section, is there any other way in which it can be added?

Lokesh.krishna (talk) 13:03, 27 December 2017 (UTC)

The USB storage devices#As normal user with mount section obviously assumes that the file system in question is writable. Without ntfs-3g, you wouldn't have success even as root. It's a problem of the file system itself, so the File systems page is a logical starting point. I don't see why there should be notes about ntfs-3g in every section related to writing to a file system. -- Lahwaacz (talk) 13:31, 27 December 2017 (UTC)
It's because it doesn't work even with root that one might get confused about what's going wrong. Maybe at least mention that the file system itself needs to be writable so that people know to take the file system into consideration when confused about what's going wrong? -- Lokesh.krishna (talk) 00:48, 28 December 2017 (UTC)
What about this? -- Lahwaacz (talk) 13:38, 31 December 2017 (UTC)