Greg Oster wrote:

> Amitai Schlair writes:
> 
> > When I swap in a drive that was part of the RAID set two weeks ago,
> > how can I be sure that RAIDframe will reconstruct _onto_ it, not
> > _from_ it?
> 
> The "old" component will have correct component numbers, correct ID's, 
> and correct "everything but the modification counter".  In that case, 
> RAIDframe will identify the old component as being part of the set, 
> but will realize that there is a component out of sync (due to it's 
> modification counter being lower) and will mark that old component as 
> "failed".  You can just then use "raidctl -R" to rebuild the 
> old-component in place (and re-sync to the good component).

That sounds hard for me to screw up, which is a desirable property of a 
backup regimen.

Speaking of screwing up, another rather important question comes to 
mind: what happens when I need to restore data? I usually won't want to 
roll back the whole filesystem to the way it was two weeks ago. How can 
I safely mount the "old" component's filesystem in order to copy backups 
of just the affected files onto the active (and temporarily degraded) 
RAID set?

- Amitai