基本上可以直接參考這篇，有些設定可以參考這篇

要多個帳號共享某個資料夾

mkdir /var/fileshare
chmod 747 /var/fileshare
mount --bind /var/fileshare/ /home/account/fileshare

nano /etc/fstab
# Add this line into /etc/fstab, so that the bind mount will still work after reboot.
/var/fileshare  /home/account/fileshare    none    bind    0       0

mkdir /var/fileshare
chmod 747 /var/fileshare
mount --bind /var/fileshare/ /home/account/fileshare

nano /etc/fstab
# Add this line into /etc/fstab, so that the bind mount will still work after reboot.
/var/fileshare  /home/account/fileshare    none    bind    0       0

暫時關掉/回復某個帳號

# take away account's password
sudo passwd -l account

# give account back his password
sudo passwd -u account