For long time as main backup solution for MySQL on Linux we have been using LVM snapshots. Performance concerns from performance critical envinronment caused us to do LVM performance research which showed horrible results forcing us to look at more performing alternatives.
Innodb Hot Backup is a good working solution but it is not Open Source and so we can’t ensure it will support all XtraDB features – extra undo slots, rollback segments etc.
After considering all alternatives we decided to develop Percona Xtrabackup tool, which will use same backup approach as InnoDB Hot Backup, that is taking online copy of InnoDB table files and transactional logs. This is going to be fully OpenSource, GPL licensed backup solution for MySQL (MyISAM and InnoDB for now).
We gathered basic ideas here http://www.percona.com/docs/wiki/percona-xtrabackup:start, and for the first stage it will be just full backup of files. For next stages we are looking to implement advanced functionality like incremental backup (copy only changes from last backup),table-level backup (copy only specified tables), streaming and parallel copying. Source code will be posted to Xtrabackup Launchpad project (https://launchpad.net/percona-xtrabackup/)
We call for more ideas you would like to see implemented (please leave them in comments). We got sponsorship for the base implementation work, but we’re still looking for sponsorship for additional features, contact us http://www.percona.com/contacts.html if you are interested. Percona will also significantly invest in this project.