chmod to make the webserver dirs writeable by the web server
chmod 0770 Enjoy your jail.
So it would be
chown root:sudo /home/sasha/web_servers chmod 0770 /home/sasha/web_servers
What do each of the numbers for the chmod do? I'm only used to three numbers.
This is the special mode, you can give it a 4 for setuid(e.g chmod 4770), a 2 for setgid, or a 1 for a sticky bit. They can be combined (e.g. setgid + sticky bit would be 3770)
As a sidenote I personally use 0710 with user:www-data on the folders.