log · this weekspotted on r/linuxquestions & the Mint forumsresolved
Q"Not authorized to perform operation" when I plug in a USB drive
The exact wording people keep hitting: you insert an external drive or a USB stick, the file manager tries to open it, and instead of files you get "Not authorized to perform operation". Or it just refuses to mount. The drive is fine. This is almost always a permissions hiccup, and it's a five-minute fix.
First, confirm the drive is really there
lsblkWhat this does: lists your disks and partitions. Read-only. You're looking for your drive. Usually sdb1 or sdc1. With a size that matches. If it shows up here, the hardware is fine and this is purely a permissions problem.
The usual cause: you're not in the right group
On Debian, Ubuntu and Mint, removable drives are mountable by members of the plugdev group. If your account isn't in it (this happens after some installs and migrations), you get the "not authorized" wall.
sudo usermod -aG plugdev $USERWhat this does: adds your account ($USER is you) to the plugdev group that's allowed to mount removable drives. You must log out and back in for it to take effect. A group change doesn't apply to a session that's already running.
Log out, log back in, replug the drive. For most people, that's the whole fix.
If it's a Windows drive that mounts read-only
An NTFS or exFAT drive last used by Windows can come across as read-only or "dirty." It's the same Fast Startup culprit from ticket #0001. Windows didn't fully release the filesystem. Boot Windows, shut down properly (or run powercfg /h off once), and it'll mount clean. In a pinch, sudo ntfsfix /dev/sdb1 clears the dirty flag. It's a quick repair, not a full disk check.
The fallback: mount it by hand
When you just need the files now, mount it manually:
sudo mkdir -p /mnt/usb && sudo mount /dev/sdb1 /mnt/usbWhat this does: makes a folder to mount into, then mounts your drive there. Swap sdb1 for whatever lsblk showed. Your files are now under /mnt/usb. Unmount with sudo umount /mnt/usb before you unplug.
If the drive uses a Linux filesystem and mounts but won't let you write, take ownership of it:
sudo chown -R $USER: /mnt/usbWhat this does: hands you ownership of everything on the mounted drive so you can read and write. Safe on a removable drive. Never run this on a system drive or partition.
The Disks app (GNOME Disks, pre-installed on most distros) can set a drive to mount automatically with your permissions. Pick the drive, open its mount options, and turn off "user session defaults." Same result, no terminal.
Question we should tackle next week? The desk reads the same forums you do. The most-asked one wins.