We too facing the similar issue. 694MB out of 1 GB used in /var/ folder. we don't know about this folder. also we don't know why this folder holds this much size.
It seems like we don't have access to these folders. Could you please help us to reduce the size of this folder.
15:08 /home $ du -hs /var/
du: cannot read directory '/var/spool/cron/crontabs': Permission denied
du: cannot read directory '/var/cache/apt/archives/partial': Permission denied
du: cannot read directory '/var/cache/ldconfig': Permission denied
du: cannot read directory '/var/lib/postgresql/9.4/main': Permission denied
du: cannot read directory '/var/lib/apt/lists/partial': Permission denied
694M /var/