pbxt-discuss team mailing list archive

[Tim Soderstrom <tim@xxxxxxxxxxxxxxxxxxxxx>]

Hi Brian!

'mylvmbackup' should take a read lock at the beginning of the backup to grab things like the binary log position when it mounts the snap. That is also required for MyISAM tables but I don't think PBXT would have the same restriction (though the lock only takes a few seconds). After that point it should be safe.

I would imagine PBXT would do some recovery just like InnoDB, but the bootstrap process 'mylvmbackup' uses should also allow PBXT to roll forward as long as the bootstrap process include the PBXT engine (which it should). If you avoid this step, it just means that restoring from a backup takes longer since it has to run through the recovery.

Beyond that, while I haven't yet tested LVM backups specifically with PBXT yet, it should be safe though there is only one way to find out :)

Tim



On Feb 16, 2010, at 12:36 PM, Brian Evans wrote:

> I use mylvmbackup to take LVM2 snapshots of files for backups.
> 
> Would there be any ramifications to PBXT to use this method as well?
> 
> I know that InnoDB does not like flat snapshots and is run through a
> bootstrapped mysqld, for internal recovery, after the snapshot to keep
> later recovery times down.
> 
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