This may happen if you have a very low ram configuration VPS with a modern OS.
The reason is that the /run mount is proportional to the amount of ram you have, you can increase this by doing the following:
append to /etc/fstab (64M should be enough for most cases)
none /run tmpfs defaults,size=64M 0 0
mount /run again
mount -o remount /run
now check df again
df -h /run