Re: LVM2 snapshot question

[Arafangion <thestar@fussycoder.id.au>]

Grant Thomas wrote:

> My main issue is using snapshots to backup a system implementing LVM2. 

<snip>

>
> The LVM howto, section 3.8, states that any filesystem that is to have
> a snapshot taken of it should be in a consistent state. I do maintain
> databases that reside on the testing server, and I am not sure how to
> verify that the filesystem is in a consistent state. 

<snip>

>
>
> Is there any suggestions, techniques or guidance that could be offered? 

I have zero experience in this, but I would suggest that an LVM-based
backup system would require stopping all services for a few seconds,
taking the snapshot, and then restarting all the services.
This makes sure that the snapshot is consistent. You can then spend the
next few hours backing that snapshot up.

With respect to databases, if you require real-time backups (ie,
bringing down the db even for a short moment is not suitable), I would
probably prefer to have multiple DB servers kept in sync, with a single
master - if hte master goes down, you have an up-to-date copy on your
slaves.

Again, I mention that I have no experience in this.