Re: Copying a disk containing a btrfs filesystem

[Michael Schuerig <michael.lists@schuerig.de>]

On Thursday 10 April 2014 19:17:13 Jan Kouba wrote:
> Dne Čt 10. dubna 2014 15:21:01, Michael Schuerig napsal(a):
> > SMART indicates that my notebook disk may soon be failing (an
> > unreadable/uncorrectable sector), therefore I intend to exchange it.
> > The disk contains a single btrfs filesystem with several nested(!)
> > subvolumes, each with several read-only snapshots in a .snapshots
> > subdirectory.
> > 
> > As far as I can tell, btrfs currently does not offer a sensible way
> > to duplicate the entire contents of the old disk onto a new one.
> Yes it does
> 
> You can make the old disk a seeding device and use it to seed the new
> one like this:

Intriguing. I didn't find much on the topic, but these pages seem 
pertinent

http://en.wikipedia.org/wiki/Btrfs#Seed_devices
https://btrfs.wiki.kernel.org/index.php/Seed-device
http://unix.stackexchange.com/a/97819/64935

> btrfstune -S 1 <old_device>

Does the "1" mean "true" or is this indeed an integer-value arg? I've 
only seen the "1" in examples, are there other possible values?

> mount <old_device> /mnt
> # this will be mounted read-only
> 
> btrfs dev add <new_device> /mnt
> 
> mount -o remount,rw /mnt
> 
> btrfs dev delete <old_device>

Is the last one the step where data is copied from the seed device to 
the second device? No balance required before deleting the device?

Thanks!

Michael

-- 
Michael Schuerig
mailto:michael@schuerig.de
http://www.schuerig.de/michael/