[linux-lvm] Which size for snapshot volume for a *safe* backup?

[Alasdair G Kergon]

On Mon, Dec 05, 2005 at 11:39:11PM +0100, Marc-Jano Knopp wrote:
> So, obviously,
>   snapshot volume size = original volume size
> is not sufficient to hold a complete change of the original volume.
 
Correct - there's a little bit of metadata required too to 
map each piece of data back into the right location.

> Btw.: There's a bug in "lvscan", it still displayed the snapshot
> as being "ACTIVE", while in fact (at least that's what I concluded),
> it was "INACTIVE" due to the lack of space, as shown using "lvdisplay".

The 'lvs' attributes should be accurate (and lvdisplay too I think).
lvscan doesn't check properly and needs fixing, thanks.
 
Alasdair
-- 
agk at redhat.com