Permission denied - USB drive

Hello,

Generally speaking, it is not a good idea to grant access rights to everyone on a key. Typically, only the user who mounted the key has write permissions on it, and that is the correct approach. When access needs to be granted to multiple users, it is better to define a group that includes the people who have access to the key in question.

In any case, all of these questions are resolved at the time of mounting the key (see command

mount

), which allows you to specify the owner user of the key, the owner group, and the associated rights to the files on the key.

In your case, the key will be identified by a device (for example

/dev/sdb1

, assuming that

/dev/sda

corresponds to your hard drive). You can find this information using the command

sudo fdisk -l

.

Next, you need to create an empty directory (mount point) where the key will appear. Let's say

/media/usb

.

sudo mkdir -p /media/usb

Then you mount the key, with the right options (once again, I insist: this is NOT a command I recommend, but it does what you're asking):

sudo mount -o default,rw,user,dmask=000,fmask=111 /dev/sdb1 /media/usb

For more details, see

man mount

and this link to understand mask issues. Basically,

dmask

and

fmask

correspond to the rights associated with directories and regular files.

To understand what follows, read

man chmod

beforehand to understand how the octal syntax used by this command is defined.

The mask values correspond to the complement (in the mathematical sense) of the mask passed to the

chmod

command (so for example, applying

chmod 755

on directories means setting a

dmask

equal to

022

). To put it simply,

mask_chmod + dmask = 777

. The principle is the same for

fmask

.

Good luck!