On 8/15/2011 6:04, Francois Labreque wrote:
>  you schedule
> the backup at the time where its least likely there will be changes to the
> file system, and pray to the deity of your choice.

You don't need to do that. You just make a virtual snapshot of the drive 
you're backing up and back that up.

> In other words, in a data center for a multinational corporation where
> planes are up in the air, or trading is going on in a stock exchange
> somewhere 24 hrs a day, 7 days a week, you NEVER have a consistent copy.

You can. That's exactly what Windows VSS is for. Linux has something almost 
as sophisticated on some of its systems.

> For systems that require a "snapshot" of the state at specific times, you
> schedule downtime at the application level and take the backup during that
> time, for that application.

You usually want to do this for upgrades and such also. Having a fixed 
schedule of downtime is useful for all kinds of stuff other than just taking 
backups.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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