Created_tmp_disk_tables  8,712  The number of temporary tables on disk created automatically by the server while executing statements. If Created_tmp_disk_tables is big, you may want to increase the tmp_table_size value to cause temporary tables to be memory-based instead of disk-based.

Key_reads  1,898 k  The number of physical reads of a key block from disk. If Key_reads is big, then your key_buffer_size value is probably too small. The cache miss rate can be calculated as Key_reads/Key_read_requests.

Opened_tables  948 k    The number of tables that have been opened. If opened tables is big, your table cache value is probably too small.