From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goffredo Baroncelli Subject: Re: Can you please define "snapshot" and "subvolume"? Date: Sat, 9 Oct 2010 15:55:01 +0200 Message-ID: <201010091555.01645.kreijack@libero.it> References: <201010072313.18647.kreijack@libero.it> <20101009081537.GA4418@glandium.org> Reply-To: kreijack@libero.it Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Cc: linux-btrfs@vger.kernel.org To: Mike Hommey Return-path: In-Reply-To: <20101009081537.GA4418@glandium.org> List-ID: On Saturday, 09 October, 2010, you (Mike Hommey) wrote: > On Thu, Oct 07, 2010 at 11:13:18PM +0200, Goffredo Baroncelli wrote: > > On Thursday, 07 October, 2010, David Nicol wrote: > > > On Thu, Oct 7, 2010 at 8:18 AM, Mike Hommey wrote: > > > > BTW, it would be very useful to be able to turn existing directories > > > > into subvolumes. > > > > > > does a (link,unlink) move work across subvolumes? > > > > The link across subvolumes is not allowable. In the beginning it was > > possible, but that was source of bugs. See the thread "Hard link across > > subvolumes" > > > > http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg03286.html > > But couldn't cp --reflink be made to work? > I don't know why, but I can confirm that in the btrfs kernel source it is checked the case that the "reflink" is preformed between two subvolume. And in this case this action is denied. http://git.kernel.org/?p=linux/kernel/git/mason/btrfs- unstable.git;a=blob;f=fs/btrfs/ioctl.c;h=9254b3d58dbef22974af3c7c61dbc9a4af7a33b6;hb=HEAD#l1489 -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512