Re: Fwd: Is there a lightweight copy from one subvolume to another?

[Marc MERLIN <marc@merlins.org>]

On Sat, Jan 25, 2014 at 09:50:48PM +1300, Maxdamantus wrote:
> Due to what I understand is some VFS limitation, you can only
> reflink-copy between subvolumes under one Linux mountpoint. If
> /mnt/btrfs1 provides access to all subvolumes, you should be able to
> copy between them through that path, but you won't be able to copy
> them across mounts, even `--bind` ones.

That was exactly my understanding too.
 
> > gargamel [mc]# cp -av --reflink=always misc/olympic Video/misc/
> > `misc/olympic' -> `Video/misc/olympic'
> > `misc/olympic/file.avi' -> `Video/misc/olympic/file.avi'
> > cp: failed to clone `Video/misc/olympic/file.avi' from `misc/olympic/file.avi': Invalid cross-device link

The test above was done in /mnt/btrfs_pool1 and failed as shown here.

Yet
gargamel:/mnt/btrfs_pool1# btrfs subvolume list .
ID 257 top level 5 path misc
ID 258 top level 5 path Video
ID 259 top level 5 path media
ID 260 top level 5 path Sound
ID 261 top level 5 path zoneminder
ID 262 top level 5 path other

Aah, but it looks like this was my problem:
'Preparing to replace coreutils 8.13-3.2 (using .../coreutils_8.21-1_i386.deb) ...

now cp --reflink works as expected.

Thanks,
Marc
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