df: `/var/lib/polkit-1/localauthority/90-mandatory.d': Permission denied
Filesystem     1K-blocks   Used Available Use% Mounted on
/cow              513416 104008    409408  21% /
udev              504752     12    504740   1% /dev
tmpfs             205368    852    204516   1% /run
/dev/sdb1         974082 709728    264354  73% /cdrom
/dev/loop0        680704 680704         0 100% /rofs
tmpfs             513416     44    513372   1% /tmp
none                5120      4      5116   1% /run/lock
none              513416     96    513320   1% /run/shm
none              102400     20    102380   1% /run/user