TokuDB Directories

TokuDB places files in various directories according to these rules:

1. The tokudb.environment, tokudb.directory and tokudb.rollback files are created in the mysql data directory.

2. The TokuDB data files are created in the directory set by the tokudb_data_dir if set, otherwise in the mysql data directory. TokuDB data files store data for TokuDB tables, and have file names like '*.tokudb'.

3. The TokuDB recovery log files are created in the directory set by the tokudb_log_dir if set, otherwise in the mysql data directory. The TokuDB recovery log files have file names like 'log*.tokulog*'.

4. TokuDB grabs an exclusive lock on lock files with names like '_tokudb_lock_dont_delete_me*'. The purpose of these lock files is to prohibit concurrent mysqld instances from using the same directories.

Given those rules, one must be careful when copying the various tokudb files around.