cd /var/lib/php
sudo mkdir emptydir
rsync -a --delete /var/lib/php/emptydir/ /var/lib/php/sessions/
#or delete using this command (wait for long time but this is working)
#First:
cd /var/lib/php/sessions
#Then:
ls -f | xargs -d "
" rm
#check count of files with "df -i" command