tablespace memory cache (3 replies)

what is tablespace memory cache ?
After I started mysql demon
why dose it happened that tablespace 18 of name './lmsgwdba/tbl_loadaverage_his.ibd' already exists in the tablespace ?

This is error message:
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140519 20:16:34 mysqld_safe Starting mysqld daemon with databases from /data2/mysql-data
140519 20:16:34 [Note] Plugin 'FEDERATED' is disabled.
140519 20:16:34 InnoDB: The InnoDB memory heap is disabled
140519 20:16:34 InnoDB: Mutexes and rw_locks use GCC atomic builtins
140519 20:16:34 InnoDB: Compressed tables use zlib 1.2.3
140519 20:16:34 InnoDB: Using Linux native AIO
140519 20:16:34 InnoDB: Initializing buffer pool, size = 32.0G
140519 20:16:36 InnoDB: Completed initialization of buffer pool
140519 20:16:36 InnoDB: highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn 1358951396
140519 20:16:36 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Error: trying to add tablespace 18 of name './lmsgwdbb/tbl_loadaverage_his.ibd'
InnoDB: to the tablespace memory cache, but tablespace
InnoDB: 18 of name './lmsgwdba/tbl_loadaverage_his.ibd' already exists in the tablespace
InnoDB: memory cache!
140519 20:16:37 mysqld_safe mysqld from pid file /data2/mysql-data/lmsgw_p.pid ended
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Please give me help..