taking lvm backup

[Tapas Mishra]

On Tue, Sep 28, 2010 at 4:12 PM, Matt Darcy
<ubuntu.lists at projecthugo.co.uk> wrote:
> Why are you trying to back the in use volumes up at a raw device level
> and not at the file system level.
I could not understand this part.
> Mount them - take a look at what's on them/size of them, back them up
> and unmount them
How do I mount them what file system type do I specify ?
If I specifiy lvm or lvm2 or none then I am getting errors.
-- 
Tapas