Disk space used but never freed from MySQL

[EvanK]

Evidently a known issue for MySQL 5.5 and below, innodb uses a single file for assorted tables' storage, and consumes but never releases disk space. This results in giant ib* files:

deploy@production:~$ sudo ls -alh /var/lib/mysql/
total 1.6G
drwx------  6 mysql mysql 4.0K Jun 10 16:49 .
drwxr-xr-x 41 root  root  4.0K Feb 23  2016 ..
-rw-r--r--  1 root  root     0 Aug 13  2015 debian-5.5.flag
-rw-rw----  1 mysql mysql 1.6G Aug 29 12:50 ibdata1
-rw-rw----  1 mysql mysql 5.0M Aug 29 12:50 ib_logfile0
-rw-rw----  1 mysql mysql 5.0M Aug 29 12:44 ib_logfile1
drwx------  2 mysql root  4.0K Aug 13  2015 mysql
-rw-rw----  1 root  root     6 Aug 13  2015 mysql_upgrade_info
drwx------  2 mysql mysql 4.0K Aug 26 15:21 wordpress
drwx------  2 mysql mysql 4.0K Aug 13  2015 performance_schema
drwx------  2 mysql root  4.0K Aug 13  2015 test