# LRU dump backup

<!-- There is a MySQL feature
https://dev.mysql.com/doc/refman/8.0/en/innodb-preload-buffer-pool.html, it
allows to save and restore buffer pool dump. xtrabackup includes saved buffer
pool dump into a backup

ib_lru_dump should be renamed to ib_buffer_pool and reference is given on mysql docs
on how to enable it -->
*Percona XtraBackup* includes a saved buffer pool dump into a backup to enable
reducing the warm up time. It restores the buffer pool state from
`ib_buffer_pool` file after restart. *Percona XtraBackup* discovers
`ib_buffer_pool` and backs it up automatically.


![image](_static/lru_dump.png)

If the buffer restore option is enabled in `my.cnf` buffer pool will be in
the warm state after backup is restored.