feature request: clone with lvm/zfs

[ufaria]

the best feature that mmm has is cloning storage with lvm when a crash happens and to be able to make a quick snapshot of storage for backup.

will be good to have these functionalities

thanks.

[yoshinorim]

How do you want to take backups?

Where:

• Crashed master: If OS access is not possible (i.e. kernel panic), we can't take lvm snapshot here.
• Candidate master or other slaves?: At the time master crashes, there may be inconsistencies between candidate master and other slaves

When:

• Before starting recovery: If you can access to the crashed master via SSH, you can take backups by implementing "master_ip_failover_script --stopssh (http://code.google.com/p/mysql-master-ha/wiki/Parameters#master_ip_failover_script)" or "shutdown_script (http://code.google.com/p/mysql-master-ha/wiki/Parameters#shutdown_script)".
• After completing recovery (but before allowing writes on the new master): You can always take backups from the new master by implementing master_ip_failover_script --start.

[ufaria]

sorry, i explain it bad. The backup is made before crash :)

the snapshot functionality of lvm is very good for this.

did you know multi-master-mysql? http://mysql-mmm.org/

[yoshinorim]

As a backup solution, LVM snapshot has serious performance problems while taking backups so I don't like it. xtrabackup is much better. Taking backups with xtrabackup is easy so I don't think I need to provide utility tools in MHA to take regular backups.

BTW, every MySQL expert knows MMM and its fundamental issues. MMM can't always work as an HA software so that's one of the reasons why I developed MHA. Please read Baron's post (http://www.xaprb.com/blog/2011/05/04/whats-wrong-with-mmm/) if you haven't.

[yoshinorim]

Closing this issue because I won't implement as a core module function.