postgres database disk issue
You can create a new tablespace on a different disk and then move those tables to that new tablespace. 

First create a new table space on a disk that has enough space:

create tablespace large_disk 
   location '/path/to/directory/with/more/space'
   owner your_postgres_user;


By making your_postgres_user the owner of that tablespace, the user automatically gets all privileges on that tablespace. 

Then you need to find out to which tables those files belong to:

select 16400::regclass, 16405::regclass;


Then move the tables:

alter table public.table_one
    set tablespace large_disk;

alter table public.table_two
    set tablespace large_disk;