Ubuntu

don't have permisson to read usb drive

Asked by rdtindsm

I have a dual boot ubuntu / windows ( vista home) computer with a 70 gig usb drive attached (also a flash 2Gb flash drive.

There are two accounts on the computer. One for me as the installer and administrator, and another for myself as user. I realize that I don't need the user account for extra security, but I am still interested in solving my problem.

As the user, I cannot read the attached usb devices. They do show up on the desktop I am reasonably comfortable with my understanding of permissions. Going into /media I see KINGSTON (flash drive) and FAT32 (external usb hard drive with permissions set to drwx------. I've tried sudo chmod 755 (and 777) from the terminal, but the permissions don't don't change. I cannot read these drives from the user account (clicking on the desktop icon). The cdrom burner also shows with permissions of drwxr-xr-x. The answers I've found in the forum tell me to use the chmod command and that it is the solution to similar questions

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Wyatt Smith
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Tomasz 'Zen' Napierala (tzn) said : 		#1

Hi,
Ubuntu security model for first created user is not administrator. You are usually using sudo for activities requiring root access, and that's the only way to do it. You should be using that account.
In other case, if you really wan't to use the other accout, add userself to following groups:
 4(adm),20(dialout),24(cdrom),46(plugdev),108(lpadmin),123(admin),124(sambashare)

Those are standard user groups allowing to use sudo.

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Tom (tom6) said : 		#2

It's not wise to make your normal user a SuperUser/Root. Administrator is powerful enough and you really shouldn't be having any trouble with a usb stick, even if you were in as a guest login.

There has to be an easy way to change the permissions on the stick or to make fstab recognise it or something like that.

Sorry i can't actually help with this problem right now
Good luck and regards from
Tom :)

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Abi ^-^ (abiyasa-eka) said : 		#3

Hello, take a look at https://answers.launchpad.net/ubuntu/+question/19357

Thank you ^-^

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Best Wyatt Smith (wyatt-smith) said : 		#4

rdtindsm

I believe that your permission problem is related to the filesystems contained on your usb devices. For example your 2Gb flash drive contains a FAT filesystem and I am willing to bet your 70Gb has a NTFS filesystem.

NTFS and FAT filesystems do not contain *nix like permissions and ownerships. Since these files do not have this these attributes, they cannot be changed with a chmod or chown. When an external device is mounted that contains one of these filesystems, ubuntu will assign *nix type permissions at the time of mount.

I would recommend creating an inode by editing your /etc/fstab. You can then select your mount options (uid, gid, umask, etc.) I would set gid=100; this should be the users group. Then make sure that your user is assigned the to the 100(users) group.

Helpful Pages
https://help.ubuntu.com/community/Fstab

For more information on mount options, open a terminal and type
man mount

scroll down to the section
FILESYSTEM SPECIFIC MOUNT OPTIONS

Good Luck

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rdtindsm (rdtinknx) said : 		#5

Thanks Wyatt Smith, that solved my question.

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bharathy (avilayabharathy) said : 		#6

But i don't have some of this group. for example:(adm),20(dialout),24(cdrom),46(plugdev),108(lpadmin)(sambashare)

And i am using Jaunty