wget --quiet -O - http://ftp.drupal.org/files/projects/drush-7.x-5.6.tar.gz | tar -zxf - -C /usr/local/share
ln -s /usr/local/share/drush/drush /usr/local/bin/drush
drush

chown -R $USER ~/.drush/

As Root
Go to example.com
mkdir -m 755 drush-backups
chown -R $USER:psaserv drush-backups