I'm running Ubuntu 14.04 on a Toshiba Chromebook 2 via crouton.

I recently reformatted a 256GB SD card that I keep in my chromebook at all times. My problem is that every time I try to access my SD card after waking up my Chromebook I am greeted with the message

Authentication is required to mount SD256 (/dev/mmcblk1p1)
An application is attempting to perform an action that requires privileges.
Authentication is required to perform this action.

Action: org.freedesktop.udisks2.filesystem-mount
Vendor: The udisks Project

I'm curious why I have to authenticate my SD card each time I wake up my chromebook and whether or not there is a way to change this.


I found the answer. This is a UDisks PolicyKit authentication issue, likely triggered by an upgrade.

The clue was a question about requiring authentication for mounting. We need only reverse it.

You need to create a file in /etc/polkit-1/localauthority/50-local.d/ called something like udisks.pkla with the following content:

[Storage Permissions]

(Note, /etc/polkit-1/localauthority and its children are only accessible to root, so using sudo may require blind filesystem access; or just use sudo vim or sudo bash and navigate there inside the editor or shell.)


I suspect it is because the mount point is owned by root, I've had that happen to me on my Chromebook Ubuntu crouton environment. Check the owner and permissions of the mount directory.

  • nice guess, but sudo chown myusername /media/myusername (perms 0750) didn't work for me. – Adam Katz Sep 30 '15 at 4:41
  • (nor did the same operation on /media) – Adam Katz Oct 9 '15 at 17:57

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