My os is debian8.cat /etc/group |grep 'debian8'root:x:0:debian8debian8:x:1000:debian8 is the member of root group.cat /etc/sudoersroot    ALL=(ALL:ALL) ALL%sudo   ALL=(ALL:ALL) ALLdebian8  ALL=(ALL:ALL)ALLdebian8 can execute any commands as root.root@hwy:/home/debian8# find / -name 'vimrc'/home/debian8/openwrt/feeds/packages/utils/vim/files/vimrc/root/openwrt/feeds/packages/utils/vim/files/vimrc/usr/share/vim/vimrc/etc/vim/bundle/Vundle.vim/test/vimrc/etc/vim/bundle/vundle/test/vimrc/etc/vim/vimrcNo Cannot chdir into mountpoint  output.    root@hwy:/home/debian8# sudo find / -name 'vimrc'Cannot chdir into mountpoint./home/debian8/openwrt/feeds/packages/utils/vim/files/vimrc/root/openwrt/feeds/packages/utils/vim/files/vimrc/usr/share/vim/vimrc/etc/vim/bundle/Vundle.vim/test/vimrc/etc/vim/bundle/vundle/test/vimrc/etc/vim/vimrcCannot chdir into mountpoint.root@hwy:/home/debian8# su debian8debian8@hwy:~$ sudo find / -name 'vimrc'[sudo] password for debian8:Cannot chdir into mountpoint./home/debian8/openwrt/feeds/packages/utils/vim/files/vimrc/root/openwrt/feeds/packages/utils/vim/files/vimrc/usr/share/vim/vimrc/etc/vim/bundle/Vundle.vim/test/vimrc/etc/vim/bundle/vundle/test/vimrc/etc/vim/vimrcCannot chdir into mountpoint.Cannot chdir into mountpoint  output for the last two situation.Why there  are two lines output  Cannot chdir into mountpoint. ?@Julie,here is what i get .    debian8@hwy:~$ cd  /tmpdebian8@hwy:/tmp$ cdNothing output.debian8@hwy:~$ cd /tmpdebian8@hwy:/tmp$ sudo bash -c cd /Cannot chdir into mountpoint.Cannot chdir into mountpoint.    Now there  are two lines output  Cannot chdir into mountpoint. root@hwy:~# cd /tmproot@hwy:/tmp# sudo su -;Signature not found in user keyringPerhaps try the interactive 'ecryptfs-mount-private'Signature not found in user keyringPerhaps try the interactive 'ecryptfs-mount-private'
Why Cannot chdir into mountpoint?
mount;find