An incremental backup produces a directory structure containing a subset of the files from a full backup. All non-InnoDB files such as *.frm *.MYD, and so on are included. *.ibd files are included only if they changed since the full backup, that is, if their maximum logical sequence number is higher than the value specified by the --start-lsn option.

$ find /tmp/backups
/tmp/backups
/tmp/backups/backup-my.cnf
/tmp/backups/datadir
/tmp/backups/datadir/ibbackup_ibd_files
/tmp/backups/datadir/ibbackup_logfile
/tmp/backups/datadir/ibdata1
/tmp/backups/datadir/mem
/tmp/backups/datadir/mem/db.opt
/tmp/backups/datadir/mem/dc_p_double.frm
/tmp/backups/datadir/mem/dc_p_double.par
/tmp/backups/datadir/mem/dc_p_long.frm
/tmp/backups/datadir/mem/dc_p_long.par
/tmp/backups/datadir/mem/dc_p_string.frm
/tmp/backups/datadir/mem/dc_p_string.par
/tmp/backups/datadir/mem/graph_dc_schedules.frm
/tmp/backups/datadir/mem/graph_schedules.frm
... many more files...