Auto-mounted USB thumb drive only has user write permission if FAT16 or FAT32
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Ubuntu |
Invalid
|
Undecided
|
Unassigned | ||
Bug Description
If I prepare a USB thumb drive (memory stick) with either FAT16 or FAT32 file systems, it will auto-mount and user write access is granted (i.e. user can drag from Home folder to USB drive folder to write to the device).
However, if I prepare the same thumb drive with an ext3 file system, the device will still auto-mount correctly, but user write access is denied.
I have demonstrated this on two different USB memory devices (old Memorex 128M Thumb Drive and a 5GB Pleomax Drive).
I used gparted to partition and format the devices.
Feisty Fawn Ubuntu 7.04 completely up to date as of 06/23/07
I followed many web search threads about people having trouble getting user write access to USB devices, but I haven't seen it trouble shot to this specific observation. I was originally trying to get user write access on my Pleomax re-formated to ext3 and notice that my Memorex was formated as FAT16 and worked just fine. So, I played around re-formating both devices to find this.
| jcfp (jcfp) wrote | #1 |
| Juan Simón (simonbcn) wrote | #2 |
| Launchpad Janitor (janitor) wrote | #3 |
This is likely to be a permission problem. Many filesystems commonly used on flash drives (like vfat) do not have support for file permission/
Ext3 on the other hand does have full support for unix style file permissions (usb drive or not), and these will be respected by the operating system. As a result you may well have insufficient rights by default to write to the filesystem as a normal user after formatting. Please mount the usb drive and then change the permissions and/or ownership in order to make the drive writable (using sudo when needed).