Re: btrfs freeze/thaw when using with LVM2

[sri <toyours_sridhar@yahoo.co.in>]

Hugo Mills <hugo <at> carfax.org.uk> writes:

> 
> On Mon, Apr 27, 2015 at 10:34:42PM +0500, Roman Mamedov wrote:
> > On Mon, 27 Apr 2015 14:55:49 +0000
> > Hugo Mills <hugo <at> carfax.org.uk> wrote:
> > 
> > > > This is strange considering that I wanted a consistent snapshot 
of 
> > > > entire btrfs filesystem at volume level.
> > > > 
> > > > Is there a way to achive this? or btrfs just cannot provide?
> > > 
> > >    No, there's no way to manage it with the current btrfs code.
> > 
> > Why not. fsfreeze, dd to a file (optionally with compression), 
unfreeze.
> 
>    OK, point taken, but if you want to use the frozen volume to make a
> file-level backup of the FS contents, you've still got to turn it into
> a block device and mount it... at which point, you get hit by the
> explosion again...
> 
>    Hugo.
> 


If I am not wrong, chunk tree represents the allocaiton block of entire 
file system. I could copy and replicate ( which will be less time 
consume) on alternate disk(s). 

For this kind of backup, either lvm level consistency or freeze/thaw 
would help.