# why does it happened?

**URL:** <https://forums.percona.com/t/why-does-it-happened/2152>\
**Category:** Percona XtraBackup\
**Created:** [June 12, 2011, 1:27am UTC](https://forums.percona.com/t/why-does-it-happened/2152 "2011-06-12T01:27:08Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![blueloveyu](https://avatars.discourse-cdn.com/v4/letter/b/c0e974/32.png) [@blueloveyu](https://forums.percona.com/u/blueloveyu)\
**Post date:** [June 12, 2011, 1:27am UTC](https://forums.percona.com/t/why-does-it-happened/2152/1 "2011-06-12T01:27:08Z")

</div>

i backup my databases with innobackupex-1.5.1, and this is error log:

InnoDB: Error: trying to add tablespace 126 of name ‘./fb/relation\_0.ibd’  
InnoDB: to the tablespace memory cache, but tablespace  
InnoDB: 126 of name ‘./fb/login\_19.ibd’ already exists in the tablespace  
InnoDB: memory cache!  
innobackupex-1.5.1: Error: ibbackup child process has died at /usr/bin/innobackupex-1.5.1 line 336.

why does it happened?