ubuntu@db2:/var/lib/postgresql/9.3$ sudo rm -rfv main/*
ubuntu@db2:/var/lib/postgresql/9.3$ sudo du -sh main/
22G	main/
ubuntu@db2:/var/lib/postgresql/9.3$ sudo ls -la main/
total 72
drwx------ 15 postgres postgres 4096 Nov 10 08:57 .
drwxr-xr-x  3 postgres postgres 4096 Nov 10 06:48 ..
-rw-------  1 postgres postgres  225 Nov 10 09:01 backup_label
drwx------  7 postgres postgres 4096 Aug 19 21:59 base
drwx------  2 postgres postgres 4096 Nov 10 06:41 global
drwx------  2 postgres postgres 4096 Nov 10 01:46 pg_clog
drwx------  4 postgres postgres 4096 Aug  3 18:42 pg_multixact
drwx------  2 postgres postgres 4096 Nov 10 06:40 pg_notify
drwx------  2 postgres postgres 4096 Aug  3 18:42 pg_serial
drwx------  2 postgres postgres 4096 Aug  3 18:42 pg_snapshots
drwx------  2 postgres postgres 4096 Nov 10 06:40 pg_stat
drwx------  2 postgres postgres 4096 Nov 10 09:01 pg_stat_tmp
drwx------  2 postgres postgres 4096 Nov 10 08:12 pg_subtrans
drwx------  2 postgres postgres 4096 Aug  3 18:42 pg_tblspc
drwx------  2 postgres postgres 4096 Aug  3 18:42 pg_twophase
-rw-------  1 postgres postgres    4 Aug  3 18:42 PG_VERSION
drwx------  2 postgres postgres 4096 Nov 10 09:00 pg_xlog
-rw-------  1 postgres postgres  133 Nov 10 06:40 postmaster.opts