I want to create multiple chroot environments, but I faced the issue with mounting devptsHere is STR:> mkdir -p {1,2}/{proc,sys,dev/pts}> mount -v -t sysfs   sysfs    1/sys/> mount -v -t proc    proc     1/proc/> mount -v -o bind    /dev     1/dev/> mount -v -o bind    /dev/pts 1/dev/pts> mount -v -t sysfs   sysfs    2/sys/> mount -v -t proc    proc     2/proc/> mount -v -o bind    /dev     2/dev/> mount | grep /root/  | awk '{print $3}' | sort/root/1/dev/root/1/dev/pts/root/1/proc/root/1/sys/root/2/dev/root/2/proc/root/2/sysIf I mount '/dev/pts' to the '2/dev/pts' directory, I will get duplicate mount points> mount -v -o bind    /dev/pts 2/dev/ptsmount: /dev/pts bound on /root/2/dev/pts.As you can see after these actions system creates two mount points for '/root/1/dev/pts':> mount | grep /root/  | awk '{print $3}' | sort/root/1/dev/root/1/dev/pts <---/root/1/dev/pts <---/root/1/proc/root/1/sys/root/2/dev/root/2/dev/pts <---/root/2/proc/root/2/sysIf I unmount the first mount point, the second one will be unmounted too> umount -v /root/1/dev/ptsumount: /root/1/dev/pts unmounted> mount | grep /root/  | awk '{print $3}' | sort/root/1/dev/root/1/dev/pts <---/root/1/proc/root/1/sys/root/2/dev/root/2/proc/root/2/sysCould you please explain to me why it happens?
simultaneous mounts of devpts
linux;mount;devices