df: `/var/lib/polkit-1/localauthority/90-mandatory.d': Permission denied
Filesystem      Size  Used Avail Use% Mounted on
/cow            502M  102M  400M  21% /
udev            493M   12K  493M   1% /dev
tmpfs           201M  852K  200M   1% /run
/dev/sdb1       952M  694M  259M  73% /cdrom
/dev/loop0      665M  665M     0 100% /rofs
tmpfs           502M   44K  502M   1% /tmp
none            5.0M  4.0K  5.0M   1% /run/lock
none            502M   96K  502M   1% /run/shm
none            100M   20K  100M   1% /run/user