Centos VPS run out of space (probably)

I have some strange problem with one CentOS VPS which hosts few websites, I think the storage is full: # tail -f /var/log/[login to view URL] 150806 0:54:35 InnoDB: Error: unable to create temporary file; errno: 28 # df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_plovdivderby-lv_root 50G 38G 9.1G 81% / tmpfs 2.9G 0 2.9G 0% /dev/shm /dev/sda1 477M 68M 384M 16% /boot /dev/mapper/vg_plovdivderby-lv_home 43G 28G 14G 68% /home # df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/vg_plovdivderby-lv_root 3276800 3276800 0 100% / tmpfs 749100 1 749099 1% /dev/shm /dev/sda1 128016 50 127966 1% /boot /dev/mapper/vg_plovdivderby-lv_home 2861600 2771499 90101 97% /home i think somehow there is no space for mysql and apache but i can solve it on my own and i need help.