Repository on LVM filesystem snapshot

[Matt Mackall]

On Sun, Jul 05, 2009 at 08:37:53PM +0000, Matt Nordhoff wrote:
> Matt Mackall wrote:
> > On Sun, Jul 05, 2009 at 04:17:22PM +0200, Lasse Kliemann wrote:
> >> Under Linux, LVM allows to take a snapshot of a filesystem.  
> >> (Solaris had a similar feature for years.) This is used in order 
> >> to take a backup (with rsync, tar, etc.) reflecting the 
> >> filesystem's state at a particular time. AFAIK there is no other 
> >> way to get that on a live filesystem.
> >>
> >> Although the snapshot is consistent in that respect that it does 
> >> reflect a state of the filesystem at a point of time, this does 
> >> not mean that is is also consistent from the viewpoint of 
> >> applications. For instance, suppose there is a Mercurial 
> >> repository on the filesystem, and the snapshot is taken during a 
> >> transaction or similar. Then the original filesystem is lost 
> >> (say, due to hardware failure) and the admin restores it using a 
> >> copy taken from the snapshot. Is it guaranteed that this gives 
> >> again a fully-functional repository?
> > 
> > Yes.
> 
> It's still a good idea to run "hg recover", no?

If hg suggests it, yes.

-- 
Mathematics is the supreme nostalgia of our time.