One of my customers wants to know the disk space usage for all of his domains in Plesk. Please find the script that I used in this situation.

if [ -d /var/www/vhosts ]; then echo -ne "nn=== WEBSITES ===n"; cd /var/www/vhosts && du -ks --exclude='chroot' --exclude='default' * | sort -nr | cut -f2 | xargs du -sh; echo "[`ls --ignore='chroot' --ignore='default' | wc -l` Sites - Total `du -hs . | cut -f1`]"; fi;

Fell free to modify.