Taking a MySQL backup using Percona XtraBackup (PXB) consists of basically two steps: 1) take the backup and 2) prepare the backup.
Briefly speaking, taking a backup means that PXB will copy all of the files from your instance and transfer them to another location. While it does the copy, it spawns a thread that will monitor the InnoDB redo log (WAL/transaction log) and store a copy of all the new redo log entries generated by the server during the backup.
Before restoring the backup into a new instance, users have to prepare the backup. This operation is the same as the crash recovery steps that the MySQL server does after a server crash.
It consists of reading all the redo log entries into memory, categorizing them by space id and page id, reading the relevant pages into memory, and checking the LSN number on the page and on …[Read more]